THe modern 'fat bike' style (~5" wide tires) is not really a good choice for general riding - they are designed for riding on soft or very rough surfaces and are not ideal for road or path use (although technically you can go anywhere, this is like buying an H1 Hummer as a commuter car) . They might also be difficult to find one in a size appropriate for you.
A good quality hardtail mountain bike will roll better (meaning you'll be more encouraged to go out riding) and will also be tough as nails. Look for a very large frame with 29" wheels.