For the $ you propose, you have several options.
You are going to have to eat it on gas mileage though. No decent off road truck is going to get great mileage. None. Just different degrees of sucky. You will get 20 if you are lucky, 15 if you are typical, less the bigger the tires/lift.
1) Last generation of ford bronco.
Bigger inside than other SUV type trucks. Might be too wide for some trails. Available v-8. Lots of aftermarket. Easy to lift. Solid axles. Terrible mileage.
2) Jeep wrangler.
Small inside. Jeep = just empty every pocket. Great off-road. Lots of aftermarket. Better mileage than the bronco, but don't expect anything great, especially with bigger tires & lift.
3) 4runner.
Mid-sized. Comes with decently large tires/rims. Needs a lift. IFS = more expensive & complicated lift with less articulation than solid axles. Toyota. Research spydertrax.
4) Land rover discovery. Larger than 4runner, smaller than bronco. small v-8. Don't buy a 2003. 2004 is the best year. Old man emu for lift. Solid axles, lots of native articulation. If you can work on cars, this one isn't bad. If you can't work on cars, don't bother. Mileage ~18 on the highway, 15 in town. Heated leather seats.
Those would be what I'd go looking for off the top of my head. Make sure you research the problems of each, as I am sure they all have their own web forum. They all have a little nit-picky issue(s), just make sure you know what to look for when you are shopping.