To a certain extent the two both help each other. Wrestling experience complements judo groundwork a bit. Judo will also complement wrestling, but I think it takes a more experience with it before you see any huge benefit to your wrestling game. It certainly wouldn't hurt.
Ditto, the ground work would really help, and vice versa the wrestling will help your Judo. Not knowing the rules of wrestling, not sure if the throws would help, but a pin is 25 seconds in judo compared to three seconds in wrestliing. There are quit a few high school guys in our judo class as well as our MMA class, they seem to do quite well.
Well, there's no gi involved, which was no problem for me going from wrestling to judo, but a lot of judo techniques that rely on the gi are either no good or need to be modified. In wrestling they have what's called the tie up and if your opponent hunches over a lot, which many of them do, he exposes himself to a lot of things like foot sweeps or uchimata. But I never even learned how to do uchimata properly until after (I think) a year of judo. There was a guy at my high school who switched from the diving team to the wrestling team as a senior and had only judo experience to help him out. He did alright.
We have some HS wrestlers that started coming to our judo club recently. They pick things up quickly and have done very well in a couple of judo tournaments. From what I have heard from them, they think judo will greatly enhance their wrestling skills.
It can't hurt. It would certainly widen your perception of grappling, especially with the introduction of jacket grips and submission holds.
