Good question. I considered building one up like you describe.
There's so much more power available from that PTO shaft than you'll ever get from an electric winch, and it's available 100% of the time. An electric winch that draws 200 Amps is only maybe a 2 HP motor and can't run under full load more than a few minutes out of each hour. A hydraulic motor is better, but you'll need 20 GPM to get up to PTO kinds of power levels; On my tractor that means a separate, PTO powered pump.
The Farmi type winch (or Farnsgard or ...) has a mechanical clutch that you can feather and control
just so. All that available power also means a brisk pulling speed: The cable moves along at a good walking speed even under load, compared to a couple of feet
per minute for a loaded electric winch. On this job we also had a heavy truck with an 8000 lb, hydraulic winch. We used it on one log for comparison, and that was it. The truck spent the rest of the weekend as an anchor. I think that those Warn, Ramsey, etc. winches are fine for occasional use (like rescue,) but wouldn't be much fun for continuous use.
There's a fella on the other board who built
his own PTO driven winch, and I was inspired, but there's too many other chores I really need to do. I finally decided to buy one instead. Ah well... Seat time on the tractor is almost as much fun as building stuff.