Why are you going reverse? I have a 3800, and have been in the market for a tiller as well. ****, they are expensive.
Also, what size are you looking at? My tires measured 60 inches, which means that the cutting width of the 60 inch tillers won't cover the tracks. Tractor supply has the 72 inch tillers for $2K, but it seems a little big. I priced a 64 inch from the local Kubota dealer, and he wanted $3150 with slip clutch (i just laughed at that).
On the gear drive, chain drive thing. Everyone I have talked to has been happy with what they have. So, I am thinking that doesn't matter that much.
Yep, I am asking you for help, even though you are on here asking for help. Kinda seems stupid of me. But I figured you have probably done some research, and I thought maybe I could pick your brain a little.