If you're looking for one to run on the 6-spline PTO shaft, I'd recommend a Prince with sufficient capacity to power the 'hoe. you don't say what tractor or hoe, so you'll have to go by the specs on the hoe for how much flow it needs at what pressure and get the appropriately-sized pump.
You'll have to excuse me, my mind reading skills and X-ray vision aren't quite what they used to be.
What make and model is your tractor, and what make and model is your backhoe? Which PTO do you plan on using? Is your backhoe set up with a reservoir to support an independent hydraulic system?
Per what Bob just posted need to know what type of equipment you have.
I modified my LW-7 BH on a Jinma 354 with a Prince pump. I had a complete post on this site several years ago with parts and the modification. If you have equipment like this I'll see if I can find the old post.