What sub and amp combination do I get?
Well, first you need to decide how much you want to pay... a good sub and amp combo (for SoundQuality) will probably be 200 ish for the sub and box, and 400ish for a good MONO, class D, SUB amp (JL Audio, Eclipse, Orion)
The SSL amp is not even a sub amp, it is a standard 2 channel amp, which would be fine if you were looking for the cheapest solution. The Alpine sub is OK, a type R would be better, but if you are going the cheap route...
You sound like the kind of person that would do well with a vehicle specific sub enclosure. This will fit in the trunk of your car, look almost stock, and some even come with an amp already installed. Links Below
Make sure that the subs and the amp match RMS power ratings, Max ratings vary so much that they do not really matter
In general over driving the speakers, will result in better sound, provided that you DO NOT turn them up all the way. (my speakers are currently overdriven 25%, with no problems going on 2 years)
Either way a good, reliable setup that will sound clean and stay that way will set you back $500-700