Deciding On our First Travel Trailer

I'm not familiar with lifetime warranties. I will say this though, all things being equal go with the dealer you like and trust the most. At the end of the day, they are going to be the ones you interface with and coordinate any repairs with the manufacturer.

All 3 manufacturers you mentioned are well established. Jayco seems to have a very loyal following (maybe more so than the other two) and have their own users forum. You may want to check it out if you are thinking about going that route.