There are a lot of options in the price range and you will get a lot of different opinions but I would suggest sticking with a ported sub for your application.
Here's my recommendations after going through more than a handful of subs over the years. These recommendations figure in QC, customer service and performance. I also highly recommended multiply subs if and when possible.
SVS PB-12nsd $769 shipped.
HSU VTF 3 MK4 $659 (on sale) plus $99 shipping
Outlaw LFM-1 EX $649 plus shipping.
I would generally reccomend the Rythmik Audio FV12 but it is currently out of stock.
Last sub is a DIY kit from Creative Sound Solutions. You just build the enclosure. $409 plus $45 shipping
The below is what I would consider a tier down in performance but still better than most available at your local Best Buy.
Cadence Sound CSX15 MK II $499