sealed Enclosure built specifically for your car $130

Polk components from best buy - $200

Alpine 6x9 coaxials from best buy - $90

Rockford dual amp kit - $173, expensive, but well worth it.

Rockford 4 channel amp from best buy - $204

Rockford 1000W mono amp from best buy - $370

2 things: 1) go with the D4 subs so you can wire them down to 1ohm and 2) Most of the things at best buy can be found cheaper elsewhere, usually amazon and ebay. So your total is $1,167 for parts. Going with a 5 channel amp would be cheaper overall since you would only have to get the single amp wiring kit, but that's up to you.

I have an Altima coupe, so my trunk is only slightly smaller than yours but space is still really limited. You should think about just having 1 REALLY good sub (like a Fi Q 12 since you're willing to spend $300) if you want a SQ build, instead of 2 type r's. It would save on space, and still sound really good. I'm not bashing alpine (they sound great), but a Fi Q is a handmade sub that will last MUCH longer and sound better.

Also, I had two amps installed last year in my car (1400W rms total) and it was enough to fry the crap out of my alternator. I highly suggest upgrading your electrical. This includes a Big 3 wiring upgrade (an easy yet tedious DIY project), a High output alternator (singer or Ohio gen are good), and a better starter battery (xs power ftw). Yes, its expensive, but worth it in the long run if you intend on changing your system out and upgrading to something more powerful.