You'll get tight, accurate bass with a sealed enclosure. The Kicker amp you're looking at will likely need at least a 4 gauge wire from your battery. Use at least a 12 gauge speaker cable from the amp to the subs. There are many different practices as far as subwoofer impedance, 4-ohm gives the best control, while 2-ohm is a good balance between control & loudness. I've never built systems below 2-ohms myself, I believe you'll give up too much driver control below that.
As far as component speakers, go listen to them in your local store(s). Sound quality is very subjective. I'm a fan of Alpine Type-R & Type-X, and Focal. Whatever speaker brand sounds best to you is the right one. Since you're using a large amp for your subs, I recommend at least a 75x4 amp, also powered with a 4 gauge cable and at least 14 gauge cable going from amp to crossover/speaker. Stick with a brand name like Kicker, Alpine (Alpine has always been one of the cleanest amps out there), etc.
There's a million different opinions out there, and the best place to start is at a local stereo shop and not a Best Buy type of store. Good luck with your system.