sound system help please

I have a 96 integra 2 dr, i want to get a nice system for it.
i bought a decent pioneer deck last year and it came with 2 free speakers so i put those in the front doors and they dont sound bad at all. Now i am going to buy a alpine type r 12'' sub but i dont know what amp to get that will work with it. im also thinking about buying 4 new infinity 6 1/2'' kappa speakers. If I get those speakers and that sub, what amp would be the best buy for me? I dont want to spend over 200 on it and im buying everything off of ebay. the guy at ultimate elctronics says i need 2 amps and he tried to sell me one for 600 bux. maybe the sub is to powerfull for a cheap amp? should i get a alpine type r 10'' instead? as you can see im confused... someone please help me, thanks :confused:

do some research and find out what the rms power on the sub is, and get an amp that has an rms within 20 watts of that, and your deck, how many watts per channel does it put out? you want that power to be equal with all of your speakers, i learned the hard =( im down like 200 becuase of it with the speakers

I haven't had any experience with Alpine subs, but I assume if you put the right amp with it and wire it correctly, they shouldn't sound too bad in whichever type of box you use. People usually use a 1-channel or "mono" type D class amp for subs since they output more power to a channel than a Class A, A/B, more than one channel amp.