I agree with others buying used is the way to go . I'm a fan of fiberglass roof and skin if possible as they generally have less seams to leak . RV's are VERY prone to leaking from the movement of going down the road . I also like a rear bath because they are generally larger AND you keep any stink far from the front main cabin area . I am also not a fan of slides , yes they give more room but more mechanisms to go wrong and additional leak paths . If the RV is not going to be under a roof structure at the RV park then a fold out awning is a nice feature . You can still eat outside if you choose to do so in the rain as long as it's not too windy , they can quickly become a sail and end up in Oz
If your truck does not have a 5th wheel hitch but does have a goose neck hitch there are adapters that can convert the trailer to the truck . Why buy a 5th wheel hitch if you are only going to move it once a year ? Large LP bottles is a good thing so check those out . RV manufacturers are a dime a dozen but generally speaking the onboard systems are fairly consistent in the way they work . Make sure you 100 % know how to winterize the unit , bad things happen when water systems freeze ! And NEVER EVER lose track of how tall the rig is as REALLY bad things happen when you do ! Have fun
