by going with an lga775 build, you're kinda limiting yourself to older tech.
i think you should switch it up to this cpu, mobo and ram.
athlon ii x2 250
asrock m3a770de am3
geil 2x1gb ddr3 1333 cas9
newer am3 cpu with an am3 mobo with support for newer cpus (including the 6 core's) and ddr3 ram.
something that i find rather strange about that site though, every freakin mobo they offer is from asrock, all am3, am2, s775, s939 and 1366 mobos are all asrock... even though the mobo i listed got a positive review, just an fyi to people who come by this thread.
also, im not so sure about that case with the psu. the case itself is ok, it's personal preference, it's the psu that i would watch out for, but i don't know if you can spend anymore money on a separate psu.