Look for "band tour buses" for sale to give you ideas. They often have a bedroom and some bunks. Consider going as big as you can. Mr. Blizz is very correct. Look in Racing Junk.com. Sometimes the racing motorhomes on truck chassis have bunks for crew. You're probably going end up at 42 to 45' pretty quick. Good luck!
Started looking for 379 Peterbilt TC, 24' to 30' box, bumper pull--but ended up w/1999 Liberty Coach conversion of 45' Prevost XLV bus. 1,000sf heated/AC'd race shop w/dump station, 50amp shore pwr where bus parks, 3 NASCAR/ARCA race cars & 26' Bravo trailer.