In laymans terms, a sealed enclosure is a box with no holes in it. You have a bandpass box (the waves from the front of the sub is channeled through a port).

Theres hardly a way to tell if that box is "good enough." You have it already, so just hook it up and see if you like it. You can use your stock radio, but you will need to feed the amp the signals through the rear speaker wires via a line output converter. That will get rid of the need of RCA cables to the deck.