Nice amp! You could drive basically anything with that beast. You should do something like a Peavey Low Rider 18 (9.6mm xmax, 18" cone obviously) in a cubic foot of enclosure pole shifted to Fc=20Hz and Qtc=0.577.
My new sub amps were sitting on my porch when I came home today, too. Although yours have 2 or 3 times as much power as mine (rated at 200W/8ohms and 300W/4ohms) I'm happy with 'em so far. For scale purposes, the AudioControl PCA3 temporarily resting atop the amps - all three of them are moving to a shelf behind my sofa, where they'll be nice and spread out - is a 1 rack-unit component. The A1's are about 1.75" thick. Right now they're both driving 1 JL 15W6 The subs I'm going to use for now - my current JL Audio 15W6 + a second one that's been sitting unopened since 1998... in Qtc=0.577 sealed boxes or JBL 2235H's in big vented boxes, I haven't decided yet. I only know that I've bought a lot of audio gear in the past week and maybe I should stop for a little while and just use what I have... - are pretty efficient down low so 200W/8ohms is sufficient to drive either one into xmax. Now, in a few months when I step up to JBL W15GTi's I might e-mail you to see if you want to trade amps, 2-for-1.
(Yeah, that's not the best picture in the world. The only digital camera I have right now is my sister's discarded 2MP Nikon ca. 1999. And it's slooow. I should buy my own but I'm too lazy. More importantly, I seriously need to organize all those damn wires!)