Serious Engine Question - 2004 450 Foreman

Well after all the mud crossing/water riding, My 2004 450 Foreman is dead. At first I thought (since it was ticking at the time) that it maybe just the valves out of adjustment. So I had them re adjusted, to spec. Tried starting it and still nothing. Re adjusted again. Still nothing. The third time and a lot of pulling the pull starter it ran but died if i let off the gas. So I took it out for a day and Now it wont start. I pulled it over and it feels like it has no compression like it normally is semi hard to pull over. So Im assuming, along with my other foreman buddies, that the rings are fried. So Im wondering if i just replace the rings, am I just gonna get a few miles out of it before it does this again? If so then would just a slightly oversized piston be a better choice right away than dealing with the rings? What are some good kits? And are they easy to do yourself? Im getting a Honda Manual from the dealer. I have a few buddies that work at a couple buddies that have worked on wheelers and at Dealers but they are unsure of what to get and so on. And what probs I might run into. What about big bore kits and how long do they last?

Sorry for the long post/a lot of questions I just wanted to share enough info.

I cant stand looking at my Foreman sitting in the garage anymore and not being able to ride it is killing me now that mud season is finally here!

Any information will be greatly appreciated! Thanks