B's vary quite a bit, there is a full spectrum from conversion vans designed only for comfortable traveling to motorhomes supporting almost full-time (maybe cramped) living, with variations that go in the direction of campers, others in the direction of party coaches. Look at manufacturer web sites to see the variations. Airstream particularly builds a variety of coach types on the 24-foot Sprinter, but Winnebago is getting there now too. Many different types on several platforms from RoadTrek.
Sizes will usually be 19-20, 21-22, and 23-24 feet, more amenities (or more seating space) in the larger sizes. My camping gear covers occasional "kitchen" needs and I could easily throw in a Porta-Potti if I thought I had a need for one.
While I use my 29-foot class C for longer term RV travel, most of my travel is in a 19-foot one-ton 12-passenger van, rear seat removed for storage of camping gear, luggage, or whatever cargo I might be moving. Seats are big enough for napping, for me at least.
I find a one-ton van is comfortable enough, rides OK if moderately well loaded (harsh when empty) but not as quiet or comfortable as a modern mini-van, or any mid-size to full-size sedan, cross-over or truck-based SUV.
A van (or conversion) of size used for making a B could likely pull your teardrop with ease, if the person renting it to you permits towing.