Need to buy the fastest compatable RAM immediately

[Spitfire7]

Hey guys,

I am building a video editing system and no one has really been able to answer my questions. I want to go with the fastest memory possible for this system below. For my mother board the fastest I can go is a DDR2 1200. That sounds good to me, but others have been saying to go with a DDR2 800 at faster timing such as 4-4-4-12 oppose to a DDR2 1200 at 5-5-5-18. This doesn't make sense to me, but thats why I need your oppinions. This is the only thing keeping me from building this computer right now. Please let me know what I should go with and would get me the best performance for editing somewhat professional videos. Thanks.

EVGA 122-CK-NF68-A1 LGA 775 NVIDIA nForce 680i SLI ATX Intel Motherboard - Retail
EVGA 256-P2-N751-TR GeForce 8600 GT 256MB 128-bit GDDR3 PCI Express x16 SLI Supported Video Card
OCZ GameXStream OCZ700GXSSLI 700W ATX12V Power Supply - Retail
Intel Core 2 Quad Q9450 Yorkfield 2.66GHz LGA 775 95W Quad-Core Processor Model BX80569Q9450 - Retail
Seagate Barracuda 7200.11 ST31000340AS 1TB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM
REID 2 Seagate Barracuda ES.2 ST3250310NS 250GB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM

So what Ram should I go with?

 

[Maziar]

I say go for a DDR2 800 RAM with 4-4-4-x or lower timings, because the difference between DDR2 800 and 1066 isn't much and DDR2 800 OCs very good too