ID Class C with full queen bed

Corner queen... plenty of those. Walkaround queen, there are a few in 24 foot "C" models, but usually those require the slide to be out to be used, and the mattress is in two sections.

If you want something interesting for a bed shape, (58" by 78", about two inches shorter in both x and y dimensions than a 60 x 80 queen), the Winnebago Trend has a floorplan (23B) with a drop down bed of that size.

Our 24 foot non-slide Class C has a queen bed. It's a fairly common floorplan for small Class C motorhomes. There's no need to go to a longer Class C in order to get a queen bed unless you want longer for other reasons.

I think most Cs over 27' have a queen bed. More of a decision may be a walk around or one sandwiched in the corner with a bathroom wall. We just did the search and wound up with a Tioga 26Q that has a queen that you can get to two sides of. 27' was the maximum length we wanted.

Our little Sunseeker 2300 has a 60x80 full size queen.

Several of them do - Forest River has a couple in this line - http://www.forestriverinc.com/ClassCMotorhomes/Forester/default.aspx?page=floorplans