is your box ported? if it is then you dont want to use tones too much lower than that. If you're in a sealed box then you should be ok.
Polk Audio & Infinity make excellent component speakers. As for a subwoofer, you can try Pioneer. They offer quite a few entry level subwoofers that will fit behind practically anything. They also offer CEA-2006 compliant amplifiers so you know any a...
I have a pioneer in my car and it was more than worth the money. Personally I've never really likes alpine that much. With them you have to do it the way they want you to. Pioneer lets you customize what you want more.