Keep the D70. I have one myself and there are plenty of things one might use it for. In my case, photojournalism stuff where transmission time is critical.

But also get the MF setup. Even if all you get is a Holga or Seagull TLR, spend a few bucks and get MF. The first time you see what kind of stuff comes out of a freakin' 6x6cm negative, you will be STUNNED, I promise.