Advice...I'm thinking of moving to class B

I've had several small TTs in the past, largest was a 22' airstream...I'm retired and always liked the idea of a small camper van and briefly owned a dodge illusion pop top...which is a minivan...it was much too small so I got rid of it and bought a 20' TT with a slide...great if it's just me but my wife has mentioned that she'd like to do a three or four week winter tour of the US west coast and maybe over to Palm Springs... This means I may be able to trade up to what I've kind of leaned towards all along...something like one of those high top Mercedes class Bs... What should I be looking for if I want roominess, a good shower/ bathroom, front and rear sleeping...of course as small exterior footprint as possible ( I know, with interior the size of a class A), and what are the possibilities of towing a small car behind? (Best types of small cars and tow methods here). I also should mention that I have a farly steep sloped driveway where this thing would be parked, which works ok for my TT, but was wondering the most practical leveling systems for a van....ramps? Thanks for any advice and I hope I've explained my requirements adequately. Oh, and cost isn't a big factor....