I would say the Ram, because even if you have a set of dual xeons, they wont do you much good with a MASSIVE scene with only 128MB of ram...

sure, the xeons would help but I'm guessing one will be used for keeping up with the scene and the other for actually calculating what you are doing but then what's the poing of having dual set up?

so, yeah, in my opinion, a gig of ram is enough.. (heck even 512 is fine)

-Emo