im trying to build a new system that will allow me to play oblivion and crysis at their highest settings without any real problems.  im tryin to stay under 1000 by cannibalizing my old system of a few parts.  im going to replace the HDD, video card, RAM, processor, and mobo.  a few questions have arisen while i researched some of the parts.  two problems are the PSU and which motherboard works with the video card i wanna get.  ill list what the system is so far:
 
CPU: Intel Core 2 Duo E6850 at 279.99
MOBO: ASUS Maximus Formula LGA 775 Intel X38 at 259.99
VC: BFG Tech GeForce 8800gts 512mb at 329.99 with 30 mail-in rebate
RAM: Corsair XMS2 4GB (2 sets 2 x 1GB) 240-pin DDR2 800 (pc2 6400) at 154 with two 40 mail-in rebates
HDD: Seagate Barracuda 7200.11 500GB SATA 3 GB/s at 119.99
 
what id be using from my old system is the PSU.  now, that system is a bit over 2 yrs old (i think).  that part is a Cooler Master Real Power RS-450-ACLY 450W PSU.  it was a great buy then and i fully figured itd last me through till my next build, but now i dont know.  plus, the MOBO i wanna use is crazy expensive and the only real reason i picked it was because i want a PCI Express 2.0 slot for my VC.  i also hear it has great cooling because of the enormous heat sinks.  now, i DONT plan on OCing anything.  i like to keep my computer running all the time and i dont want to worry about aftermarket fans and coolants and such.  whatever the CPU comes with, for instance, i plan on using (or i can always reuse my old systems Thermaltake CL-P0114 120mm Cooling Fan/Heatsink).  oh, and im gonna use my old tower (Thermaltake XASER, Armor Series VA8000BWS ATX Full Tower).  the other stuff isnt much important, but it will be 2 DVD-RW drives, a 3.5 floppy (yeah, i said it), a sound card, an ethernet card and a dial-up modem (yes, again, i said it...).
 
so what do u guys think?  would all that work?  can that MOBO use that VC or do i have to use an ATI Radeon instead?  should i even use that MOBO if all i want from it is a PCIE 2.0 with great heat sinks?  is that RAM inexpensive cause its crappy?  will that PSU work with this build?

oh, and i keep reading the OS is an important factor.  right now, im running XP Pro.  i know that its only a 32 bit OS and 4GB of RAM wont be fully used, but im not sure if there are any other drawbacks.  should i go to Vista 32 or 64, or is XP Pro fine for this build?

If you want to run Crysis at the highest level suggest you look at the follow
http://www.extremetech.com/article [...] 414,00.asp
http://www.tomsgames.com/us/2007/11/02/crysispc_part2/

hmm... ya know, that helped me out a bit, definitely.  especially the first link... but what about all those other questions i had?  this is really just me tryin to figure out how to best spend 1000 on a computer build.  could someone help please with those first questions?  i know im stickin to win. xp pro, but i still dont know what to do, otherwise...

I'd suggest P35 mobo it will run Crossfire but not nVidia although it will run a single nVideia card.  Most reviews suggest you're better off with one good GPU rather than 2 lesser ones.  As for specific mobos your best choices would be the Gigabute P35 DS3L or ASUS P5K E, the latter has a lot more features and so I think it's more "future" proof. You'd get a better bang for the buck with an E6750.  For a GPU, the 8800GT seems to be in the sweet spot right now.  A 64 bit OS will recognized 4GB of RAM but not sure the improvement would be that noticeable.  If it were me and if fit my budget after everything else, I'd bump up to 4GB but I wouldn't sacrifice something else for it

but what about a PSU.  should i get something more than 450w?

^Yes! Defenently more than 450W. Get a top tire PSU listed here:
http://www.xtremesystems.org/forum [...] p?t=108088

I would recommend a Corsair 520HX or 550VX.

For Motherboard get a P35-DS3L/R. This is because Intel will be switching to Nehalm end of this year and you will need a different motherboard + CPU + possibly DDR3. So just save the $100 by going with the P35-DS3L.

thanks for the PSU help!  im stuck on whether or not to just go with the e6850 and 8800gts 512mb (g92) or go with an e6750 and 8800gt 512mb.  the later will definitely save money, which IS important.  but the former provides some definite better results (plus, it comes with crysis which i was gonna buy anyway).

so far, im definite on this:
http://www.newegg.com/Product/Prod [...] 6822148288
http://www.newegg.com/Product/Prod [...] 6817341002
http://www.newegg.com/Product/Prod [...] 6820231122

but stuck on this:
http://www.newegg.com/Product/Prod [...] 6814130312
http://www.newegg.com/Product/Prod [...] 6814130319

http://www.newegg.com/Product/Prod [...] 6813127030
http://www.newegg.com/Product/Prod [...] 6813128059
http://www.newegg.com/Product/Prod [...] 6813131196

http://www.newegg.com/Product/Prod [...] 6819115028
http://www.newegg.com/Product/Prod [...] 6819115029

even still, its extremely difficult to decide whether or not to go with even a different mobo... i know what i want out of one is great heatsinks, at least six total PCIe/PCI slots, and a really good format (like how asus turns their sata connectors to face in a better direction and less crowding around the dimm slots so my long VC actually has some good clearance)... i just dont know whats more reliable and what would be best to spend the money on...

Looks like you're at the point you just have to make some decisions.  Given you want 6 SATA, you down to the ASUS or ABIT at the same price but with ABIT you'll wait for a rebate.  They're both good companies and as far as I know there are not problems with the ASUS, if I were buying, I would get it.  Looked at the ABIT board but no rebate when I looked so not considering it.  I have a number ASUS boards and have been happy with them.  Check out this chart and decide if the 6850 is worth the extra cost.  Keep in mind with performance just because something test faster doesn't necessarily means it noticeably faster and when this happens. the higher speed is not worth the price premium.  There is also a video card chart but no sure if those cards are on it.  That's the problem with choices, eventually you have to make them    
http://www23.tomshardware.com/cpu_2007.html
http://www23.tomshardware.com/graphics_2007.html

Don't get an E6750 or E6850.
 
The E8400 will be out next week and Cost as Much as the E6750 and will be faster than the E6850. (Initial Demand will cause the E8400 to actually cost a little more than the E6750, but Tray price from Intel is the same.)

i see... well, after reading this:
http://www.xbitlabs.com/articles/c [...] fdale.html
there's NO WAY im gonna buy the current processors... it now becomes whether i should get the E8400 or the E8500... oh well...
guess the only thing im still stuck on (especially now since i dont know which mobo will work with the E8400 or E8500) is what mobo to use... the ones im thinkin about dont SEEM to have great heat sinks... but i dont know... is there an updated mobo review somewhere?  ive read everything i could on tomshardware already... id love to know which u guys chose and why and if u have any recommendations of ur own.