Tweeter is dropping Eclipse, I'd go find two Eclipse Aluminums (selling them around $200 each) and power those with the 1200.1, ported or sealed, your choice, either would slam. Wire to a 1 or 2 ohm load, depending on if you get the SVC or DVC models (I'd get the SVC and run 2 ohm with that amp)
The number to Eclipse tech support is 1 800 233 2216 if you want to make sure, I'm not totally certain of the recommended box as calling them is about the only way you'll get that info from them (or email tech support) They're open 8:30 to 5:30 Pacific standard time.
I'm really considering getting the 3 Shiva's but on there site it says i'd have to run 3 of them at 5.something ohms....anyone know if thats right or wrong? whats the Ohm rating on a shiva?
If you are going to spend 150 per sub . thats around 450 total. get 1 Brahma. Ive heard things about this sub and that it is AMAZING. I would get that or a RE X.X.X