I'd recommend a Freightliner MT45, or any type of similar aluminum body Step Van with a Cummins 5.9/6.7 engine. Old Fedex/USPS delivery trucks. Good fuel mileage, easy to work on, lots of room, can find em at auctions for well under $5,000. Thats what 3 of my friends have done. My best friend as been living in one for 3 years. The automotive vans just don't seem like a enough space.