I planned on debit free Full Time Rv'ing and have not regretted it. Paid cash for my MH.
Regarding the accessibility of a MH due to health issues.
I would look into the Class C and Class A "toy haulers".
http://outlawrv.com/These are full MH's but are equipped with a garage door that comes down. My friends with disabilities and/or are wheel chair users have bought this type of RV and it works great for them. Not only easy in and out but a place to bring with and store a full size wheel chair or scooters.
They make TT toy hauler's also if you have and/or can use a handicap accessible equipped tow vehicle. But the added price of converting the truck will add substantially to the cost of your RV set up.
http://www.generalrv.com/product-dutchmen-rv/rubicon-toy-hauler-travel-trailer