Re: Class C with only overhead bed

Winnebago Trend 23B has a sofa bed and a power lift/lower bed also, I believe. NOTE: The Trend has been discontinued, so used may be your only option there.
If you're looking for short, perhaps a Winnebago Era with a murphy bed that would be out of the way until required. It's a Class B Van. Not real short, but close.
You can check their floor plans at Winnebagoind.com