If you want a minivan, then according to Consumer Reports the Dodge/Chrysler comes in a distant third. Tied for first is the Honda Odyssey and the Toyota Sienna.
They all come in various levels of trim and "stuff". My current '05 Odyssey is near the top of the line with leather, GPS navigation, rear seat DVD entertainment, power sliding side doors, 3-cylinder deactivation, hole in the roof, XM radio, etc. Cruising at 74 MPH it gets a true 21 to 22 MPG. But the sticker was $34,610, not counting the distributor pack of floormats and other geegaws.
The next model up also has run-flat tires and a power tailgate. I could live with the power tailgate, but they can keep their run-flat tires - so I didn't get the Touring model.
My next one will be either an Odyssey or Sienna, but they can keep the leather, navigation system, rear seat entertainment, and hole in the roof. If it's a Honda, I want the EX model because of the better engine with 3-cylinder deactivation.
My Odyssey has over 100,000 miles on it now, but it's going to have to last until the stock market and the price of crude oil rebounds some.
Ancient history - I bought a new 1988 Plymouth Grand Voyager with the Mitsubishi V6 engine. It was a good car for 20 years ago, but I traded my '86 Toyota Camry LE stick shifter for it, and it certainly was not the car the Toy was. But I needed the room so Darling Wife could comfortably lie down during the long trips from Denver to west Texas several times per years. We put over 100,000 miles on it with no problems other than folks bumping into Darling Wife on snow-slick streets in the Denver 'burbs.

But I wouldn't buy one today, because for a few more bucks you can get a much better vehicle screwed together by Honda or Toy workers in the good ole USA.
I've seen several minivans converted to a ramp side door for a wheelchair or scooter access. One today was called a "RampVan". Right down your alley. They're in Orlando, so maybe not too far from you?
The Ramp Van - HOME
Before my first wife died, she had lost one leg and was in a wheelchair. I bought her a '94 Ford E-Van, then had a wheelchair lift added for side-door access. There's a lot more headroom in an E-Van than in a minivan, but gas mileage is not as good. I double-checked with my dealer a few weeks ago and you can still order the 2009 E-Van with the diesel engine. Before you spend the big bucks, you should probably try out both a minivan and a full-size van to be sure you can put up with the cramped conditions in the minivan.