I know you want output, another great way to go would be to do a custom box with 1 x 15" TC-Sounds driver and 2 x 18" PR's, you can tune it to what ever you want... and the output would be spectacular...
Just 1 of those boxes will be far more output then the sealed box you did already in the crusher
It'll take far less power as well.... you could make them fit in that space, and also have them look absolutely beautiful if you choose... you could find a cabinet maker in the area and see what he will do for ya...
Parts Express
That'll get you way under budget and also get you a custom looking product that your wife can approve of.....