I have been looking on this site and others at used 5th wheelers and tow trucks. It seems there is no shortage but being from the UK it's hard to get my head around the size of the USA. Anyhow I think I want something between 30 / 34ft . We will be staying for 4 months can anyone advise if there is an ideal size ie: do all RV Parks / campgrounds accept all sizes, are there any pitfalls to using larger or smaller units? Also what size / make of truck?