to be really honest, find the board you want on newegg and then go find it on tigerdirect. newegg reviews are a lot more accurate, and there's a lot more of them. just sort by number of reviews and you'll be fine.
i can't remember the last motherboard that had 2 pci-e slots and didn't have 3 pci ports, so you're fine there. assuming you're going athlon (the intel e8400 is still $160...!), stick to the newer models if possible. a 3ghz dual-core processor looks sexy until you realize just how slow the damn thing is. you get what you pay for.
don't reuse your DDR sticks, buy new ram. it's a significant speed difference, and ram's so bloody cheap you can get two gigs for 25$ at most.
psu = power supply unit (gee thanks google). use the extreme power calculator to figure out the minimum watts you need, then add between 20-25% for the effiency rating (if you multiply your efficiency rating of your psu by the watts that it's rated at, you've got how much it feels comfortable putting out). try to hit the 60% range for the amount you'll be using on a normal basis. shoot for two rails if your graphics cards are more than a year old or not that great, or three if they are newer or pretty hungry.
if you've got questions about PSUs, my guide in my sig has at least eight or nine pages on information about them. there's a summary at the end of the chapter that'll help.