Building a gaming rig, need some advice

These are the parts that I need immediately:

Motherboard
CPU
RAM

For this, I am definitely planning to go with a Core i7 x58 setup, with 6 GB of the maximum supported frequency of RAM. I was looking at these parts specifically at this time:

Motherboard:
ASUS P6T Deluxe V2 LGA 1366 Intel X58
http://www.newegg.com/Product/Prod [...] -_-Product

CPU:
Intel Core i7-920 Bloomfield 2.66GHz 4 x 256KB L2 Cache 8MB L3 Cache LGA 1366 130W Quad-Core Processor
http://www.newegg.com/Product/Prod [...] -_-Product

RAM:
CORSAIR XMS 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 Desktop Memory Model CMX6GX3M3A1333C9
http://www.newegg.com/Product/Prod [...] 6820145259

Overclocking is a maybe for me, and I'm almost certainly going to go with SLI one day. That being said, I'm not completely dead set on these products, if there is something better then by all means, I'll take a look at it. I got the first two components from a guide on this website, and I'm partial to Corsair RAM. Like I said, however, I'll look at anything that is potentially better. As far as overclocking, the motherboard that I listed supports up to 2000 MHz OC I believe. I don't think I'd go that high, but probably a notch below that, if that helps at all. I'll provide more details if necessary.

These parts are a maybe:
Video Card
Hard Drive
Monitor

These are the parts I currently have:

ATI Radeon x1650
http://ati.amd.com/products/RadeonX1650/index.html

WD Caviar Blue 250 GB, SATA 3 Gb/s, 16 MB Cache, 7200 RPM
http://www.wdc.com/en/products/pro [...] riveID=298

I can't remember the exact model number, but it's a 21" Samsung LCD SyncMaster with a 2000:1 contrast ratio and I think 8ms response time.

I know that my video card is crap, and I eventually want to move to SLI/Crossfire, but I'm wondering if it's worth it at this point, or if I could wait a while longer and get something better down the road.

I eventually want to get a WD Caviar Black HDD, but I'm not too concerned about it right now. SSD isn't going to do much for me I don't think, so I'm not too interested in that. I do plan to get a TB Caviar Green for storage at some point as well.

As for my monitor - the main thing is that it doesn't support HD at all. Is this going to be truly important for gaming? How much of a difference does it make from standard DVI? I've seen the difference on actual TV, and it's quite significant, but I'm just wondering if it's worth it to shell out the extra money for an HD monitor, and/or if it's worth going to non-HD SLI. Some input here would be fantastic.

Things I'm interested in:

I'm pretty much dead set on the i7. With that being said, and with my particular needs in mind, would I need an aftermarket cooler for the CPU, RAM, or anything else? Like I said, I do plan to try out overclocking at some point, so if I would require some thermal paste, an aftermarket fan or anything of the sort that would help with my computer's heat, I will take any and all input into consideration.

Also, I do plan on buying a gaming keyboard at some point, and I'm wondering what some of the better ones out there are. I went to Tigerdirect and saw a couple that looked really nice, specially the Logitech G13 I think it was. It looked quite impressive to me, but if there are better options out there, I'm more than happy to listen.

As far as power goes:

This is my current PSU:

Ultra Products XVS Modular 600W ATX Power Supply
http://www.bigbruin.com/2006/ultraxvs_1

I'm thinking about upgrading to this:

CORSAIR CMPSU-850HX 850W ATX12V 2.3 / EPS12V 2.91 80 PLUS SILVER Certified Modular Active PFC Power Supply
http://www.newegg.com/Product/Prod [...] 6817139011

My biggest concern with my current PSU is the 78% efficiency rating it has at idle. I'm wondering if the parts I plan to get will make upgrading my PSU a necessity, and of course, as with anything, any alternatives and any other input is highly appreciated.

As for my case, and I'm probably not going to change it:

Ultra E-Torque ATX Mid-Tower Case
http://www.tigerdirect.ca/applicat [...] CatId=1859

The moment I set my eyes on this case, I wanted it badly. It has served me very well since. I'm wondering if I would even need an upgrade on this case. As always, any and all input is greatly appreciated. However, I will not settle for anything less than all the features that my case currently has. Somehow I anticipate that this one is worth keeping, but I'm not 100% sure either.