Hydrostatic Transmission - Required HP?

I'm thinking about converting my build to a Hydro, this would save a lot of headache for the build. I just need to make sure that a 15hp single cylinder motor will not be a problem.
Thanks for your help guys!

It should be fine. I had a 15 Horse Kohler that was on a craftsman with a hydro. They come factory that way.

15 horse is plenty

Alrighty guys, I'm going to buy it! I just hope it can handle what I put it through

314.0510 Hydro Gear
This is what I ended up picking up, It looks like it will work real nice for my tractor. Any one ever convert one of these to a chain drive? I need to find out what the diameter of the puller bore so I can order a sprocket for it. If I can't get the fan to mount back up I'll use a 12v electric fan over it to keep it cool. Today, I disassemble the parts tractor

I don't know how that one will do in your lifted JD. I have a Husqvarna with a similar trans in it. It's feels pretty weak. I don't know though. Should be interesting to see how it does.