The amp doesn't really matter. Find whatever you can that fits your price range. You'll ant a 300-400w at 1 or 2ohm (what coil config did you get?) or a 150-200x2 at 2 or 4ohm.
Sealed boxes can sound just as good as ported, and if built correctly can be louder and go deeper. However, throwing subs in a cookie cutter box wont yield this. The box you want depends on your listening preferences. If you just want to be loud, you'll want a big ported box tuned higher (35Hz +). However, that wont be able to drop.
Give us some details like what sort of sound you like, what vehicle, how much room you are willing to give up, and what your music preferences are.