I was just thinking OVERCLOCK! but i read the rest of your post and you said "BTW Im not planning to overclock anything" Hmmm um I had to underclock my 1333 to like 1200 or something because it wasn't stable at my FSB speed 2300mhz :3 1333 should be cheaper i guess. If you want really really really really nice ram check out Corsair, I got G.Skill DDR3 which is great too. 4GB should be ok. I did notice a huge difference going from 3 to 5 gigs
ALSO you want dual channel right? I think you can only dual channel on 3 or 6 gigs, i don't exactly know though.