I am using an Alpine MRD-M1005 amp:
1000W rms 2ohms, 700Wrms 4Ohm

http://www.crutchfield.com/S-3bd3SWk3qsE/cgi-bin/ProdView.asp?search=m1005&i=500MRDM105

Looking to spend around $200-400

Was thinking about 2 Alpine SWR-1222's or maybe a an Alpine SWR-1542. Which would push more air? Two 12's in a small sealed or one 15 in a nice big ported box? The box volume will probably have to be under or around 3.5ft^3 to fit in my trunk.

Links to the Alpine subs:

http://www.crutchfield.com/S-3bd3SWk3qsE/cgi-bin/ProdView.asp?g=520&id=detailed_info&i=500SWR1542#T ab

http://www.crutchfield.com/S-3bd3SWk3qsE/cgi-bin/ProdView.asp?g=520&id=detailed_info&i=500SWR1242#T ab

 

Also the subs will be going into the trunk of my '97 Toyota Avalon, if that makes a difference.

 

Im going to say a single 12" liek an RE xxx or something bigger to run off that amp..get some SOLID bass :d

 

A single DD 12" in a HO slot port box would do the job just right.

 

Definetely go with one bigger sub. You could get a nice 15 in a ported box, and that would **** for sure. An RE SX15 or DD3515 would be pretty wicked.

 

I am thinking of going with two Diamond D615D2 in a sealed enclousre. Any comments, suggestions?

 

Just go nuts, and go ported, you'll be happy with it