For a mid to higher quality sub and amp here is the setup I would recommend.
Sub
P3D412 - Rockford Fosgate Punch Stage 3 4-Ohm 12" Subwoofer
Amp
ZX750.1 - Kicker 1 Ch 750 Watt ZX Series Amplifier
Power Wires the reason I choose kicker is because they have a very good quality wire and very easy to work with.
Amazon.com: Kicker 05PK4 4-Gauge Single Amplifier Power Kit: Electronics
RCA's
Stinger makes some pretty good rcas and you need a quality set so that way you do not get much noise interference from other electronics in the car.
Amazon.com: SHI2312 - Stinger 12 foot - 2 Channel HPM3 RCA Cables: Electronics
Now if you want to get a little better quality here is your other choices.
Amp
X600.1 - Phoenix Gold Xenon 600 Watt Mono Amplifier
OR
PDX-1.600 - Alpine 1 Ch 600 Watt Digital Power Amplifier
Sub
KAPPA PERFECT12VQ - Infinity Kappa Perfect Series 12" VQ Series subwoofers
IDQ12V3.D4 - Image Dynamics 12" IDQ Version 3 Dual 4 Ohm Subwoofer
Now the reason I choose the subs I did was because not only your taste in music but how much power you are going to probably be running and also your budget. Any combination of sub and amp would sound good from this group. If you wanted me to choose I would choose the PG amp and the ID Q sub, I think that would sound pretty darn good. Also JL DOSE make some nice subs and yes they sound good but there are better ones out there for the money and will also sound better.