I think the biggest issue you will encounter is PTO speed. Front mounts run off the crankshaft, mid PTOs run at 2000 rpm. The rear PTO is 540, possibly with 2-3 speeds, at 750 & 1000. If you are handy, you might be able to get something together with big pulleys. If you are buying driveshafts, housings and gearboxes, you may end up near the price of a 48" bush hog or finish mower.
Most of the time you spend a couple of days cobbling something together, and end up with something that looks cobbled together, that you would not want yours or your neighbor's kids to be around.