Hi, and welcome to the forum.
I would review this website for TT (travel trailers) and 5er's. You should check out the brand on the RV Consumer Group web site, which is the RV bible that every RV Dealer goes by. Here is the link. http://rv.org/
I think the first year's cost is $140. Which may seem like a lot of money but if you are going to full time in a 5er, then you will want a unit that will withstand the rigors of full timing.
I would check out Arctic Fox 5er's I have also heard very good things about them and I believe these models are highly rated. Another model of 5er's to check out is Mobil Suites.