In my 04 Explorer I had a 12" Hifonics Brutus driven by a Crunch 1001 and it sounded amazing. I went cheap in my wife's ride since she isn't picky and just wanted some bass to round out the stereo. I was literally blown away. Talk about bang for you buck. You can get the amp and sub cheap too at www.cardiscountstereo.com (around $200)
Crunch power ratings are inflated but they are still insanely powerful for the money.
If you are wanting an amp and a sub, you need to be ready to cut some corners somewhere. Dont get me wrong, JL subs are awesome but they aren't cheap. Id avoid the low end MTX and JBL subs too. Ive had them and was not impressed with either.
Oh and for the record, a friend had a Kicker 15" l7. I tried it in place of the Hifoncs and it didnt sound as good. It hit harder but sounded fake.
Try one, you'll not be disappointed.