A Ranger Super Cab should have plenty of room for you. You can adjust the seats much more than in the regular cab, plus the dry storage space is convenient.
I have driven my '02 Ranger Super Cab 3.0 from NC to VT/NH, and many times to AL and back, and never wished I had something else. It works great as a daily commuter vehicle and on long trips with no passengers.
My truck gets about 22-24 MPG on the highway, which I consider pretty good for a V6 automatic pickup. A Duratec I4 should do noticeably better than that and is still a pretty peppy engine. The Duratec was available in Super Cabs from 2003 on and is pretty common on '10/'11 Super Cabs since the 3.0 was dropped.
Personally, I really like the 3.0 V6. It tows a 3,000+ lb trailer nicely and is a great highway cruiser. Fuel economy in town and on E85 isn't so great (15-17), but the highway fuel economy is good. It's not the most powerful engine or most economical, but it is very reliable and good in all other aspects.