Get a Pulldozer.
Ryan has been building winches since 2005 and he knows what he is doing. He is constantly improving them and they are getting even better and better. He actually rides as well as listens to feedback.They are consistent and very easy to drive (which is super important!). They also have all the features you need when winching (break, wheels, stake holes, hitch, and they are light enough to carry). And he prices them well.
I have a had a lot of friends build winches, but there are so many variables and they end up being extremely inconsistent and ruin a lot of trips.
I have ridden behind a handful of homemade winches, Integrity Winches, Yankmeister, Grinch, and a few others, but nothing is as smooth and consistent as a Pulldozer. Winching is enough work, so it's nice knowing you dont have to worry about the winch.
I'm not affiliated with Pulldozer in any way. I have just had too many winch trips ruined because of garbage winches. And honestly, it's scary riding behind an inconsistent winch. Whether you are jumping down a drop, or hitting a rail, you want it to work perfect.