I dont knwo too much about computer parts and I have been wondering, generally, what is going to run faster; 2 one gig sticks dual channeled or just 3 gigs? (two 512s and two 1 gig sticks) Or as a second option if the two 512s are able to be dual channeled and the two gig sticks can also be dual channeled can I dual channel both sets at the same time? Thx in advance.

Hi and welcome to PCHF

Crucial.com has a memory configurator that will scan your system give you what options are good.

Memory upgrades from Crucial.com - Determine My Memory Needs

Their RAM is great quality too... but you can of course buy wherever you wish. Just don't buy "Joe's super-cheap RAM" or the like-- you'll regret it.I have no affiliation with Crucial... but I run their RAM
other good brands are
Kingston
OCZ

You can dual channel both at the same time (as long as your motheboard has 4 slots, of course) as long as they are the same speed.

Which ever config you go for I recommend running memtest after to make sure all is well.