depends on the box requirements of the subwoofer when you make a box that large cubic feet wise. One thing youll want to realize is that it wont take as much power to reach full excursion and you may not be able to tune your box very low as a result. Two ports however is fine it will just take more depth of the port when you go from 1 to 2 to match a given port tune (ex. 35 hz 10 inches deep with one port 35 hz 13 inches depth with two ports...each port of equal length) Generally you dont want to go more than 2.5 times the recomended box size.
what do you mean "nasty" ? nasty as in horrible or nasty as in bad as$,awesome,etc. ? By the way I'm gonna give the Orion 1200d a try. its rated at 1200 watts rms x1 @ 1 ohm. Ive heard nothinkg but good things about this amp. My other 15's x.x.x. I just to run them with an Infinity1200a(1200rms x1)each and they pounded so fu[ken loud. we'll see how this Orion does.