POSSIBLE AMPS FOR THE FIQ 18"AQ 1200/2200
Hifonics....
Sundown 1000/1500
Kicker...expensive
what about Kenwood-there really cheap
If you have 1500 watts on tap, that is more than enough to get the Q moving. The AQ1200 would work perfectly fine. You aren't going to notice a huge difference between going from 1000 to 1400 watts on the Q. I didn't notice a difference going from 1200 to 1500 watts on my Mag.
If you plan on ever upgrading in the future though, I would definitely pick up the AQ2200. Then you have enough power to add an additional Q in the future, or if you decide you need to satisfy SPL needs, you can get an AQ 18", or nightshade, or whatever! And power it perfectly.
Point: Anything over 1000-1200 is overkill unless your upgrading. AQ1200 or Hifonics1606 would work fine.
Don't forget, install is much more important than the sub and amp itself. I am not sure what your plan is for building a box, but box will be a
huge factor in how clean your Q sounds. The 18" Q could sound just as clean as a 10" Q in the right enclosure, don't let anyone tell you otherwise, they don't know what they are talking about.
EX. Sealed is supposed to sound "tighter" and "cleaner" than ported. I built my own sealed box, and although I thought it was pretty good, and sealed, it still sounded a little muddy. I bought a ported box from BJ Fisher (who I recommend) and it sounds
much cleaner and tighter than my sealed box ever did. And much much louder.