You can use regular sheets and suspenders to hold the fitted sheet in place. Use two separate suspenders, not the kind that are sewn together, and make a big "plus" under your mattress with them. We like 100% cotton sheets and haven't been able to find them in a camper queen size so this worked great for us. We also use a regular comforter set since the one that came with the camper was just too darn itchy for our liking.
Tim & Joy
2011 Sierra 365SAQ
Reese 16k Hitch
2007.5 Chevy 3500 Crewcab LTZ Diesel