Help me decide on things

[mokkapoop]

Howdy, I was incouraged to come here for any questions I have on computer, so here I am.
I have around $2100 to spend on a gaming machine. However, I am having a hard time deciding on what to buy. I am determined to go AMD 64 939 (currently have 3000+ 64 754) but I cant decide on this. Tell you what, I will just list below what I have thought about:

Cpus:
Athlon 64 3200+ 939 Venice chip 2ghz 512kb cahce - $192
Athlon 64 3700+ 939 San Diego Chip 2.2ghz 1mb cache - $228

Video:
Of course this will be PCI-E
SLI OR NOT TO SLI? Please tell me if this is really worth the money, I am an avid gamer and will be playing Battlefield 2 when it comes out soon, so please help me deicde wether to go SLI or SINGLE card.
Single Gigabyte x850xt with VIVO - $480
2x BFG 6800GT for SLI setup - $370 each

RAM:
OCZ 2x 512mb pc4000 at 2-2-2-8 $185
or 4x 512mb twin mos pc3700 at higher timings - at $86.87 per 2 sticks

PSU:
OCZ mod stream 520wt

MOBO:
DFI Lanparty UT nf4 SLI-DR - $174

Main thing is just help me decide on CPU, VIDEO CARD, AND RAM. Thanks to all in advance!