Have to admit, the pictures here are great - some really nice looking "this isn't suburbia" lawnmowers.
If budget isn't a consideration, go get a zero-turn. When it gets too troublesome to fix in a few years, go get another one. Repeat as necessary. I know a guy doing just that (more money than brains). If you want something that will still be working long after you want to, or can:
First choice: Cub Lowboy.
2nd: Farmall Cub with a belly mower
3rd: Super A with a belly mower
I've used my SA with a Rhino 3pt finish mower, and it does a really nice job. I've also used the SA with the mid-mount A-22 sickle bar to mow the lawn - no problem getting close to trees, fences, or mowing the road ditch. Sure beats the push mower, or Craftsman rider (mower spindle been broken for 2 years, deck rusting out, and no good reason to fix it).
And unless you have no trees, firm soil that a narrow front won't cut up, and a tall garage or shed door to clear the muffler, a Farmall C is probably too tall. Definitely overkill as just a lawnmower. Then again, Tim the Tool Man would probably disagree. (Ollie 1855... no, JD 4850... go big or go home: CaseIH 9370, 360hp with duals all the way around, yeah, for the lawn... de-thatch, fertilize, cut, bag, compost, roll, and all in a single 50' swath).
Now watch someone post a picture.