Best used truck for pulling horse trailer, skid steer?

I'm trying to decide on a model of used truck that has the power to pull a horse trailer with two horses, or a trailer with a mid-sized skid steer, but gets better than 8-10 mpg. I'd like an extended/crew cab and 4 wheel drive. 90% of trips will be less than 20 miles. However, a few times a year may do trips around. 700 miles. We'd like to spend less than $5000.