i suggest you go with
Blaupunkt, even their old cassette radios are insane, the sound is awesome, of course if your speaker setup is well done, same for the sub, as for speakers, dont go with anything less than
Infinity they are THE best speakers, my buddy got the whole
Kappa set, the front which are 4:6 plus two tweaters. amd rear 6:9, it sounds as if he has a sub and mad amps, but just has the speakers and a JVC face plate
dont BUY a prebuilt sub case, they are ****ty, you have to have it done custom to your car, and they are stupid to built, just need some good wood, carpeting to match your car, and all the sites selling subs have plans to build your own case according to your car, and your setup for optimal performance, because you can get mad bass without having a mad sub, just a well done, well sealed case, yuo can check if it leaks with smoke, fairly simple. check out infinity
www.infinitysystems.com/