My advice is to go with Kicker or Alpine for subs. And ignore all inflated wattage numbers - unless it is RMS it is BS. Sealed box is more controlled sound but if you want the big bass thump go ported but make sure the box specs are right.
I have a 180w RMS bridged amp driving a single Kicker Comp 10" 150w RMS ($45 from Best Buy / Amazon - goes on sale all the time) in an ATREND 10SQV ported box ($45 shipped on Amazon but out of stock there now) and it rocks the car for $100. And fits in the trunk of the coupe / vert (12" height limit).
http://www.bestbuy.com/site/Kicker+-+Co ... Id=9892463
http://www.atrendusa.com/atrend/pro-ser ... gory_id=35
You could probably fit 2 of these if you wanted. Of course the hatchback has unlimited space - I would look at dual Kicker 10's or 12's (the cheap Comp ones unless your amp is high RMS power) installed in a box from eBay or Amazon seller with a great reputation / review, like this one here.
http://www.ebay.com/itm/KICKER-DUAL-10- ... 1e6956a6cc
Remember you need a good amp for any sub. SONY, Pioneer, Alpine, Polk, Kenwood & Rockford Fosgate - these amps I would trust. There are other good amps but there are a lot of junk cheap crap amps out there ready to ruin your setup. I personally would avoid Boss, Hifonics, Lanzar, Pyramid, Planet Audio and any amp that does not prominently display the RMS wattage. 1000w for $44 shipped on eBay isn't going to cut it.
Good luck!