What enclosure do you plan on placing them in? I ask because a well built enclosure custom tuned to the vehicle it is going in will sound much better off of lower power than an improperly built enclosure with all the power you can throw at your subwoofer!
With that said, a JL Audio 1000/1 will be more than adequate for a pair of TW5s. Don't let the haters on this forum get to you with their mumbo jumbo about JL Audio being overpriced, or you can get better for less. They are just jealous because they can't afford it OR mommy and daddy will only buy them Hifonics!