I had an old 1962 cub cadet 10 hp that was built like a tractor, clutch, 3 speed gear box, tractor type rear back tire.
Wasn't much of a lawn mower. Deck was always eating a bearing. Took 2 acres to turn.
Not sure they make tractors like that today.
People who are in to lawn mower tractor pulls like this old girl because of the tranny and rear axle.
I would avoid using most of today's mowers to pull with. I have a troy-built and pulling would eat the two belts that connect to the rear end. Those belts aren't cheap. Not too much fun to replace either.
IMHO, the best puller would be to find an old mower that used an actual gear box. However I haven't seen any sold in the past 25 years. I have an old craftsman with that tranny. Put tractor tires on it and use it to pull 2 atv type three ft disks. The worst thing is you may need to replace tranny belt, which is cheap and easy to do.
My 15 year old john deere GT275. It has a better hydrostatic tranny and tractor bar type rear tires. I have a 30 inch tiller, so hydrostatic is needed. It would make a good puller. Also have a 4 ft mower deck. Both are easy to take off and put on. Must use JD deck and JD tiller.