i personally wouldn't throw 2000 at the Q, thats 1000 over the rated rms, i would get a BL fully loaded and that should take 2000 watts. and according to Fi, the minimum ported box for the Q should be 6 cubic feet, 6-10 @ 28Hz is the reccemended box size from the fi website.
i have about 11 cubes net but i want to keep space. and i have 3000 watts to play with. how about 2 18s sealed? maybe 2 18" bls? or q's. most likely q's since they're cheaper