Yup, I'll second what Old said.
It's REALLY nice to have the independent hydraulics that a separate pump and tank will give you. And a pump that runs off the FRONT CRANK is much, much, better then running off the PTO (leaves the PTO free to power other stuff). And, to me at least, power steering is almost a neccessaty. Otherwise, it takes all the fun out of tractorin'! Good luck!