Pie, I don't know how much you're looking to spend.
Brushless is great if you want to put that much money into it. If you don't, then I think you'd be happy with a normal brushed 540 motor. A 540 motor is the standard sized car/truck motor that you'd see in 1/10 scale. Sometimes you'll also hear 540 motor being called 05 motors....same thing.
Does your truck also come with a speed control, or do you need to pick up one of those also?
-Bryan