If money mean nothing I would get 2gigs of ram. Depends what you do but if you into any kind of video rendering and stuff you can easily use more then 1gig of ram. I have 2gig of ram in my system and sometimes uses almost all of it.
the ram I recommend is
OCZ 2GB (2 x 1GB) 184-Pin DDR SDRAM
This ram awsome for just about anything.
It cas 2 for a reasonable price (try to find any other cas 2 1gb stick for around this price). It one of the few 1gb sticks that perform just as well as any 512mb stick.