Need input on new system and RAM

[AgentWD40]

Hi guys. I'm new to these forums (first post), but would like to impede upon the great wisdom that lies within.

I am building a new system to replace my "Gaming" Laptop (a P4 2.6 gHz, 512 Megs RAM, Radeon 7500 Mobility). I maily play Counter-Strike Source (although play might not be a good word, more like yell at my screen for the low FPS and lag) and would like to play Battlefield 2 and maybe FEAR Combat.

This is a budget computer because I am pratically broke but can not stand to not play anymore.

I have ordered a ASUS P5ND2-SLI board off ebay for $40. I also picked up a nVidia Geforce 7900GS at woot.com for $140 (plan to pick up another one later for SLI when they are released in retail). I plan to purchase from newegg.com the following:

Pentium D 805 ($97, I plan to overclock to around 3.5 gHz or so)
Cooler Master Centurion 5 case ($45, side question - Will this case be cool enough for my needs?)

Also looking at a Ultra X2 550 watt PSU from ZZF.com for $99 (is this a good choice for my setup?).

I have a couple hard drives and optical drives laying around so no problems there. I would like to get the best RAM for my money. I budgeted $85 for RAM and would like 1 gig. Should I go with two 512 meg sticks in dual channel config, or will one 1 gig stick do? And would DDR2 667 bottleneck my system or should I go up to DDR2 800?

That brings my total to $421 plus the cost of RAM. My goal was $500 so I think I will be close.

I know I ask a lot of questions, but would greatly appreciate any input that I receive! Thanks!

 

[J Macker]

I would not purchase the Ultra psu. A much better psu for virtually the same price can be had:
http://www.hardforum.com/showthread.php?t=1089416
tested stable at 668W SLI certified, and the v4 is actually capable of 18A.

I built a friend's computer last month with the Centurion 5 with a 120mm Scythe Ninja for the cpu. Temps are around 70C full load, be sure to buy a couple of case fans.
So, yes, the case is fine for cooling, as he still has not had any heat issues at his house with no A/C and 100F temps outside. Inside his house is high 80's, gets to low 90's. yuck!

I would definitely purchase the DDR2 800 in a 1GB stick, so you can purchase another stick in the future.
Be aware though, that the P5ND2-SLI does not like OCZ ram. I had to ship the ram back to newegg and buy some trusty Corsair. This was the case for me. The motherboard manual states which ram is compatible.
http://support.asus.com/download/download.aspx?SLanguage=en-us&model=P5ND2-SLI Deluxe

kinda funny how I happened to just build a system with the same case, mobo, and ram not too long ago. I did purchase a FSP 450W for him though as he was only getting a 7600GT and no plans for SLI