Need some advice on my Build! XEON or X2 or Optoron

Hi my PC died last week and Im reduced to researching my new build at the Library(limited to 2 hrs per day on xtremley slow pc + connection)
I need to build a new PC within the following budget:

I have new 2 x XEON 3.6Ghz 2Mb 800fsb for free that i could build a system around or i could sell them and put the money to a new system.....

eg.
Athlon 64 X2 4200+ Skt939 2.2GHz 512KB Processor
245.81
A8N32-SLI Deluxe Sock939
140.22

Crucial 2GB kit (1GBx2) DDR PC3200 CL=3 ECC
DDR400 2.6V 128Meg x 72
138.64
XFX Geforce 7800GT 256MB PCI-E 2xDVI TV
219.33
WD Caviar SE 250GB 16MB SATA II 7200rpm
59.28

Nesteq Semi-Fanless ASM PSU, 620W
139.99
Antec P180 Advanced Super Mid Tower Case
79.67
---------------------
£1022.94/$1926.81

I am looking for:
Low operation noise.
Good performance in all areas of PC use for the money, including gaming
Avoiding overclocking, as i dont want to risk damaging hardware or shortening its lifespan, although i am open to persussion!

Possible expansion:
Raid 5(3xSataII:2xstripe 1xbackup)
2 x 7800GT 256MB, although i seem to be picking up some negative vibes regarding 2 card systems, Could i use the other slot for something else???

Also if sum1 could reccomend a really quiet, efficient, cheap and compact CPU cooler for this system

I cant really go over my budget, Im gonna have to wait a few months for a new screen, so if i do go over its gonna be for cables or something...

Would really appreciate some feedback,

Yeah, those are $650+ processors new, sell them if you can. You'll get better gaming performance out of an AMD X2 anyway.

I don't know why you've got CL3 ECC memory in there, but I'm not sure it will even work with your setup, plus ECC is more expensive (and unecessary for you). Get some good CL2, non-ECC memory. And don't buy a 7800GT, buy a 7900GT (or two if you want), same price and more performance. It is clear that in most newer games (games developed after the SLI/Crossfire thing started) perform better with two cards, so if that is within your budget go for it. You didn't actually mention what your budget was though.

For cooling, tom's did an article on a bunch of relatively cheap air coolers, do some browsing around the site to find it and that will give you a good starting point.

Thanks for the replies...

My budget is around £1000/$1.889

Even with an expensive server board/case from SuperMicro + Dimm's, the XEON system works out about the same as the proposed x2 system, mainly because the free processors cover the extra cost, so it really just comes down to what will perform better.

The memory was selected using Crucials 'memory selector system' using the motherboard model number.

Whats the differnence between the Opterons and the X2

I would recommend going with the duel opterons, your performance is slightly better with duel cpu compared to a duel core and it is also cheaper to purchase 2 cpus than a duel core cpu, though the mobo is cheaper for a single cpu socket, the price will come out to about the same, though with opterons you will also be more future proof.