What would be the best press to get for lots of different size ammo?
I have a Lee Precision Classic Turret Press that I've been very happy with. It's easy to switch back and forth between calibers and it won't break the bank. Here's a link:
4 Hole Classic Turret Press - Lee Precision
With a little practice you can load hand gun ammo at a rate of about 150-200 rounds an hour pretty easily.
A single stage press will get you off an running for even less money, but they are far less convenient to use.