In reply to Lynsety:
I have an Outwell Montana 6 and it's MASSIVE and pretty much bombproof. There are five of us, husband is 6ft 3 and can stand up in it. We have a trestle type table which goes up with chairs around it, inside. No problem at all.
It is a heavy beast and probably would be more than your budget new, but I got mine as an ex-display bargain a couple of years back, it's worth looking out for end of lines and second hand maybe.