the 6600le is a turd go for the 6600GT if you can it will get you closer to twice the FPS.
Go for branded but cheap ram (such as crucial) as latancey dosen't matter much on pentium 4 systems at the moment.
Two completely incorrect statements, I'm afraid mate. ;)
The 6800LE, when "unlocked" will actually out-perform a 6600GT. - Not for nothing did I happily swap my 6800GT back to a 6800LE.

Low latency RAM is certainly beneficial on P4 (and most other) systems.
memory: 2.5, 3, 3, 8 Duel channel on
Is your memory having a fight? or do you mean "Dual" ?

Posting drivel here since Jan 31st, 2002. - That long!
"He who laughs last, thinks slowest."