Hey there, building a new gaming pc, these are my two possibles:

RAM: corsair 4gb (2x 2gb) DDR3 1333mhz xms3 memory kit Cl9 (9-9-9-24)
CASE: Antec 902 Nine Hundred Two Black ATX Case - No PSU
HDD: Western Digital WD5000AAKS 500GB SATAII 7200RPM 16MB Cache - OEM Caviar Blue
OPTICAL DRIVE: Sony AD-7240S 24x DVD±RW DL & RAM Internal SATA Black Bare Drive - OEM
CPU: Intel Core 2 Quad Q9550 2.83GHz (FSB 1333MHz) Socket 775 L2 12MB Cache Retail Boxed Processor
GRAPHICS CRD: HIS HD 4890 1GB GDDR5 Dual DVI HDTV Out PCI-E Graphics Card
MOTHERBOARD:
PSU: Corsair 550W VX Series PSU - 120mm Fan, 5 Year Warranty

and

RAM: corsair 4gb (2x 2gb) DDR3 1333mhz xms3 memory kit Cl9 (9-9-9-24)
CASE: Antec 902 Nine Hundred Two Black ATX Case - No PSU
HDD: Western Digital WD5000AAKS 500GB SATAII 7200RPM 16MB Cache - OEM Caviar Blue
OPTICAL DRIVE: Sony AD-7240S 24x DVD±RW DL & RAM Internal SATA Black Bare Drive - OEM
CPU:Intel Core i5 750 2.66GHz Socket LGA1156 8MB L3 Cache Retail Boxed Processor
GRAPHICS CRD: HIS HD 4890 1GB GDDR5 Dual DVI HDTV Out PCI-E Graphics Card
MOTHERBOARD:
PSU: Corsair 550W VX Series PSU - 120mm Fan, 5 Year Warranty

They are the same except for the different cpus, so far i hav not got a mobo, can any1 suggest to me good mobos for either or both of these builds? cheers

Hi Gamerdude,
I'll mark this as Open to encourage those who know to respond
Thanks for your patience

1st off, you're negating the advantage of speed offered by DDR3 RAM by buying CL9 (9-9-9-24) sticks. Look for CL7 (7-7-7-X). Low latency is more important than sheer speed (frequency). CL7 is more expensive than CL9 for that reason.

ok then hows about Kingston 4GB (2x2GB) DDR3 1333MHz HyperX Memory Kit CL7 1.5V? and also, do i need a fan/cooling system SPECIFICALLY for the ram? i dont do i? and also for the pc shud i go with windows 7 32 or 64 bit?

You should be safe with any DDR3 RAM that's described as 'optimized' (or whatever word they choose) for i5 CPUs if you go that way. The newer DDR3 RAM operates @ a lower voltage than DDR3 RAM that's been out for a while. Your motherboard of choice will specify a voltage range for the RAM. Better yet, after picking a board, go to the product page and check the QVL (qualified vendor's list) for RAM suppliers. These lists are notoriously out of date and/or limited in scope, but as new as the i5 form factor is, that list should be current but not all inclusive. It doesn't get any easier does it?

A fan shouldn't be required for the RAM unless you're overclocking the dookie out of it. Lots of fans circulating the air inside your case will be sufficient.

I'll eyeball some motherboards and get back to you with my take. Do you have LOTS of money?

to be honest no, not lookin to spend any more than like 150 VERY VERY MOST on mobo cheers again

Kingston is fine but I'd recommend going with DDR3/1600 kit (4GB). For motherboard on the i5 I'd use the Gigabyte GA-P55-UD5. It's gotten good reviews and you SLI/Crossfire compatible. For the Q9550 I'd use the Asus P5P43TD Pro. Support DDR3 as well