I don't know how large you are and it varys but some of the overhead beds have a limited weight capacity (ie: they are really for kids), so check that out before buying.
Depending where you are there are lots of big RV dealers around where you can wander 10-20acre sites and look thru various RV's but that wasn't so much my point.
My point was how do you intend to use the RV?
Even the class C units over here are usually 24'+ with many pushing 30-35' and with the wide open spaces and large camp sites, it's no more difficult to manuver them. On the road, it's pretty much irrelevant.
You may want to reconsider the small MH as you will have to pack up camp to see anything or get into town to buy food or other necessities (some people do it and love it but it's far less common).
A larger MH towing a small car or a truck with trailer works better here because there is space for them and once you are there you have a vehicle to go see the sites while the RV stays at the site set up.
Now if you go to a campsite, set up and never leave, it will work fine if you don't mind the lesser room.
