Yeah, he sells JL and he's sponsored by them, and shows his Av for them.
Now as for the question, go and listen to some speakers at local stores/shops. Listening to them on a sound board in a store is totally different than listening to them in a car, but it's better than nothing. If you go to some independent shops, they should have a demo car or customer's car sitting around that you can check out and listen to.
Your ears will tell you more about speakers than all of the collective knowledge on this board, simply because your listening tastes and habits and your hearing will dictate what sounds good to you.
If you definately want one of the two you listed, they both make reputable products to fit just about any budget.