wirsig,
Okay, the point of my comment was what do you want to do with the airplane?
The Maule is relatively small, compared to the other two. Useful load is quite small, compared to the other two. Speed is likely faster than the other two. Can carry lots of gas, or very little, depending on how much range you need, and how much load you can leave at home.
The Helios are fantastic performing airplanes. They are getting really hard to find. They are not difficult airplanes to fly, but they are VERY different airplanes to fly. This is an airplane that just won't work for you if you try to fly it like other aircraft. Flown well, there is simply nothing on the planet that will touch one for back country flying. There are turbo charged versions, so density altitude is less of an issue. Maules and Founds are NOT turbo'd. There is a turboprop version of the Maule, though--you just can't carry enough gas in those.
The Bush Hawk is a heavy duty, big airplane. It has the same airfoil as a DC 4, and it flys sorta like that, too. If you are a low time tailwheel pilot, the Bush Hawk is probably the easiest tailwheel airplane to fly I've ever operated.
You can buy a Found and a Maule new. All Helios are pretty old.
MTV