Have you though about making the steeper slopes in to flower gardens. There are many flowering plant, bushes, and ground covers that can be used in these areas. Naturalizing these slopes would add to your yard's appearance if done right, dand increase your safety.

To properly evaluate your needs for a mower, it would help if we knew any special physical needs you may have and he size of your lot.

Hmmm, you didn't mention budget?

Chains and mowing are kind of mutually exclusive for safety reasons. You might consider going to a Ag type rear tire or a "rough" ATV tire and dispense with the chains.

Servicable transmission just put you into the $3000+ price point and even then you have to be careful. e.g. I was looking to replace a GT (Garden Tractor) last year and looked at a Husqvarna and was told that the trans was servicable. Under pressure, the guy admitted, "Yeah, it's servicable, but to change the fluid you have to pull the trans, turn it upside down and leave it for a week to allow the fluid to drain through the fill tube."

I'll let other folks advise on Zero Turn units, I do know there are now a lot more of them in the lower price ranges, but personally suspicous of them for that reason.

A couple years ago I would have suggested Sears who always has good sales going, however, don't know how long Sears will be around. As Sears doesn't make anything, parts are readily available from whoever originally made the machine. However, don't know how handy you are or if you have access to someone to do that.

It's always a good idea to try to buy from a local dealer, e.g. JD if they have a good service reputation. Buying from Big Box stores can be tricky in terms of service even if you buy the extended warranty.

Good luck,

Ev