Which Memory to choose?

[gl600]

Hello,
I'm building a gaming machine and i'm looking at these 2 memory options but i do not understand the diff. between them (the technical language is lost on me... I'm learning...)
Anyways, the price is about the same. If anyone can help out and let me know what the practical diff between the 2 is, i'd really appreciate it!
Thanks.

option 1)
2GB DDR2 PC8500 DUAL MEMORY / Kingston KHX8500D2K2/2GR / HyperX Memory Kit
* Type: DDR2
* Capacity: 2 GB (2x 1GB)
* Speed: PC8500 1066MHz
* Size & Bit: 128M x 64
* Pins: 240pin
* CL5 (5-5-5-15)

option 2)
4GB DDR2 PC2-6400 DUAL CHANNEL KIT/ (2X2GB) / OCZ / VISTA UPGRADE EDITION
* 800MHz DDR2
* CL 5-6-6-15
* 4GB (2x2048) dual channel optimized kit
* Unbuffered
* Copper Mirrored XTC Heatspreader*
* Lifetime Warranty
* 1.8-2.0 Volts
* 240 Pin DIMM

 

[Poizen22]

get crucial balistix ddr800, it will run 1066mhz very easaly.

 

[csaefong]

the diff between them is hte pc6400 has a slower speed then the pc8500 but i think if you buy the pc8500 you will have to clock it to pc8500 because i think when you install them they are set at pc6400 settings.

 

[Puddle Jumper]

get crucial balistix ddr800, it will run 1066mhz very easaly.

I agree. Newegg has 2x 1gb Crucial Ballistix Tracers for $39.99 after MIR.

Newegg.com - Crucial Ballistix Tracer 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail

The only difference between the tracers and the regular ballistix is the tracers have led lights and in this case the tracers are also cheaper.