Do you mean that you are getting Kappa components, and infinti rears and a 12" sub that you are going to run off just one amp? If so you'll need something with multiple channels. Here is my favorite if I was going to do a dobly 5.1 system in my car for DVD audio.
model is D65.2 has 7 channels, 5x 60W, and 2x 70W. Awesome amplifier for an all in one system driven amp. If I ever switch from 2 amps to just 1 that would be it. Although it is slightly expensive. That is the price you pay for quality. They are designed and built in the USA, and if Installed by an authorized dealer, comes with their lifetime warranty.
Alpine also makes a theater amplifier. Here is theirs; Model is MRA-D550 here is a link to Alpines product pagehttp://
www.alpine-usa.com/en/p...-D550 If you want to check it out.
If you just want to run front speakers and a sub you can use either of the two four channels I mentioned in the previous post. just bridge the rear channels to the sub only. And turn on the X-over for low pass here are links to the picture I posted. This is a cheaper option but could still result in a good sounding system.
http://www.alpine-usa.com/en/p...-F545 http://www.diamondaudio.com/pr...EARCH
Happy Hunting.