First Subwoofer.

I am going to build my first subwoofer using this woofer
I am thinking of using the Apex Jr amp and will be using this for music and movies but mainly music. I would also like to keep the enclosure reasonably sized. Should i go sealed or vented? What are the advantages either way. I`m not looking for very high volumes, just good solid bass to fill in below my fostex 167s.
Ok, so you got around 1.5 cu.ft internal to work with.

The Rythmik Audio A250 Basic is a 250W plate amplifier for 119$, if you can afford it, it's better than the PartsExpress one.

You should go sealed with a 16x16x16 box with this driver. Going ported that small is hard to do, also a ported enclosure that small doesn't give much gain over a sealed enclosure.