If you're just looking for one to get started with, then I second Adrian's notion about getting a K-3 to learn on. I was just going through this process myself a couple of months ago, and after doing some research I realized that in order to shoot my films the way I wanted AND do it on 16mm then my only realistic option would be to wait until I could afford something like an Aaton XTR or Arri SR3.
Rather than delving straight into purchasing a $2,000+ camera (which, just to put this into perspective, is actually quite cheap), I decided to just find a decent enough camera to help me learn how to shoot film and settled on the Krasnogorsk-3. From what I've seen on Ebay, they can go for $100 to $250 or so, but I got mine for a really good deal at $60 after shipping and handling. It was a bit of a gamble, but considering these cameras are known for being hit or miss anyway, I figured the sting wouldn't be too bad if it didn't work correctly. Fortunately, as far as I can tell it is in great condition, though I haven't had the chance to shoot with it yet. I'll get back to you all on that when I do. ;)