If money is an issue I would definitely look on sounddomain.com at the Boss Redd series subs. I have a 10" and my friend has a 12" and we both love them. They are rated 250RMS and 300RMS respectively, have huge magnets. I don't know if I would give them much more than they're rated ( I don't think my amp really puts out the 250RMS that its rated at), but they take good bit of power. People are probably going to tell you to stay away from them, but they have some higher end features at low end cost, and I really like them. In terms of amps there are plenty out there that will drive one or two subs without a problem. I have a Crunch and again I love it even though its a low end amp. Its all about your personal preference and how you set up your system. For example I spent $500 on my system. Got all new door speakers, sub, 4 channel amp drives them all, plus my headunit, and I made my own subbox. My roomate wanted rockford stuff, so he spent $500, got a 2 channel amp, like 150x2 RMS, 2 12's, and a clarion headunit. His headunit tweaks out his factory speakers way before the headunit hits its potential and the bass drowns it all out anyway. Keep this in mind when setting up your system. If you have a 35w RMS headunit that should be able to keep up fine with one 10 or 12, maybe even 2. You should be able to get exactly what you want well within $400.
