re: 5th Wheel RV assistance

Brands: Jayco if you can get one in your price range. Other good ones have been mentioned here. You may also want to look at Puma 5ers. Stay away from Fleetwood products, they're known in RV service departments as "Leakwoods" for a reason.

Features: With kids, get a bunkhouse (as previously mentioned by others).

Also consider construction; aluminum exterior is cheaper to buy and repair, but also easier to damage. A good hail storm can total an aluminum exterior camper. Filon (the smooth skin put on as an entire sheet per side) on the other hand is lighter and easier to maintain.