No concerns carrying the tractor. Highly recommend the berm / ditch trick at each end. And, either remove the tailgate, or span the tailgate with your ramps. I recently transported a concrete buggy in the back of my truck (1000 lbs). No problem loading it (ramps and a berm) but when the single tail wheel pressed on my tailgate, it put a good dent in the middle. Never had a problem with the tractor, as it has 4 wheels, but this had a center wheel, and I only had 2 ramps and a short board so all the weight pressed on my tailgate. should have removed it.
I built my ramps from 8' 2x10s, to which I nailed a 2x4 on edge to each side. The 2x4s provides stiffness, and keep the wheels on the ramps. I used a strap hinge to attach a 12" piece of 2x10 on the one upper end, and that stops the ramps sliding off the truck bed as I go up. Nailed some shingles to them for traction. Use them for everything.
My biggest concern is securing the load. I feel the tie downs in my truck bed are pretty flimsy for 1000lbs and I sure don't want that sliding forward hard!