As far as RAM goes, I assume your friend wants 6GB as his mobo is triple channel.
I recommend Corsair memory, as it seems to be the most reliable.
This set is a bit pricier than the rest, but has the best reviews and big, solid heat sinks. Because even RAM has to stay cool and look cool when your case has a window.
As far as the DVD drives go, so long as your friend doesn't want blu ray, any one of the
generic drives should be fine.