Do you have storage underneath the bus?
Having "too much space" is so much better than not enough. More space gives you options.
A 30-34' Gooseneck would probably work well.
As you shop for a trailer, be aware that driver licensing is much less dependent upon length than it is GVWR. Combined (truck/trailer GVWR rating cannot be over 26,000 pounds without a Class A CDL. This is not "as it sits" but what it is RATED to weigh.)
We just bought a 48' gooseneck for our 4A program. The TRAILER has a GVWR of 24,000. Add that with our 1 ton dually...you see where this is going...