Hello Jim,
I saw your other post about ZTR's somewhere, but thought I would post here. I am sure you realize that money can get you just about anything. I have used Dixie Choppers for about 20 years, and they are a very good mower. And I still have them. I have cut lots of hills, some as much as 40 degrees, but with a technique that I developed. I had to do this because of what I had to work with. No matter which ZTR you get, they will all slide down a wet steep hill. I learned a whole lot in about 20 seconds, by sliding down a wet hill that I had been cutting for 8 years. I slid down this hill about 30 ft, and then dropped another 5 ft off the edge down to the next level. I also had a front counter weight.
I would have different manufactures/distributors, bring out different mowers, and let them show how they are supposed to cut. A new guy not familiar to ZTR, will not know what , or how to use it correctly.
What you should be looking for is a low center of gravity machine, with as much HP as needed, and I would recommend Kohler. Tires that are a combination of lugs and bars for gripping power. A ROPS bar installed, which can also be used for shade with some adaptation. A machine that is easy to work on. Just for instance, I can fix just about anything on my Choppers. Parts, I can get from almost anywhere. Reliability, check the history on any machine as to factuality, and durability, etc. Determine whether you like the mower deck out front, or in the middle of the machine. They also make front cut flails, which do an excellent job in a variety of situations. If you cut near water, think carefully about seat-belts. Check out how the machine can be moved if broken. High lift blades or Gator blades, etc. Can you tow small trailers with it. How easy is it to attach a vacuum system to the machine. Does the machine come with a grass catcher.
The trick to cutting steep hills, is to cut up at a 45 degree across the hill, and when you get to the top, turn slowly and go down the hill at 45 degrees, at idle speed, and use the hydro to keep you slow, and use the brakes sparingly . Keep doing this until the hill is cut. If you should loose traction, prepare your self for a fast bumpy ride. with no control. Take your time and test all you want. Four wheel drive would be a plus.
You just might find a good deal on a good used machine.