You can buy slimline subs to fit behind the seats in utes, you just need to get creative when designing the box. A few brands do them, Pioneer, Blaupunkt, JL Audio spring to mind.
Check out this thread for suggestions on brands in different price ranges.
Mate your not gonna get much help, asking for brands and set ups, you havent even mentioned a price range, who will be fitting it, .......Brand means nothing really, comes down to what sounds good to the person buying, at the price they want to spend.. The benifit's on a ute install, whatever you put in is going to be a lot louder overall, due to the small cabin space. You could go nut's and put a set of splits in the doors, and a pair in the space behind the seats. Add slim line sub behind each seat, and you'll have enough noise to give you a right headache!!