Way back when I cut my teeth on car audio I dealt almost exclusively with JL and Kicker for customers. JL's are pretty decent subs, but they like a fair amount of room to breath properly. The recommended enclosures from JL are more SQ oriented than volume, but a good sized box around 2.5 to 3 cubes at 32hz for a 12 w3 is a good compromise between SPL and SQ for example. If you're hurting for space and you've never had a sub before I'd get a 10 in a solid enclosure.
Depending on your budget, the w3, w6, and w7 are all good options, obviously getting better as you go up. The w6 is probably a good middle ground for you. I wouldn't get a w0 though. Of you're on that tight of a budget, look at another brand.
JL is expensive, but it's good. Worth the price? To me, no. But I have different tastes. Itll sound really good if you do it right, so if you're set on it, you won't be disappointed. Just a bit broke
On a side note. I wouldn't go with a complete prefab set up. Do some research, download winisd v7, and see what you may or may not like. You can have a great set up and save some coin by putting your own system together around just the sub, what ever you get.