if u're funds are 760 ish then maybe look at getting the 8500 over the 8400, higher multiplyer will help with the overclock.
if you're not looking to overclock too much then i'd drop the mobo to something like the gigabyte ep45 ds3.
memory wise make sure you get something decent, geil black dragon for pc6400 seems to clock well or some pc8500 if the price is right.