go with something like polk audio, alpine, boston acoustics, kicker and use composite 6 1/2"s in the doors, most come with crossovers to keep the bass out of the tweeters. best place for tweets is either in the a pillars or at the bottom corner of the a pillars at the windshield. you can use tape to mount them temporarily till you find the best place to aim them. If you know how to do fiberglass you can pretty much build any enclosure you want. I just got a brand new pair of polk audio 4" 2 way speakers for $18 (retail for $80) but an odd size , i plan on fiberglassing the lower door panels and mounting them alongside the 6.5's
I never seen the mopar subwoofer but i'm guessing thats its wayyyy overpriced for what it is. but if your using the stock head unit then i guess thats the only option, maybe a bazooka tube
http://www.sasbazooka.com/, or something similar taht has a built in amp. In order to run anything else you would need to have rca outputs from your head unit to an amp. I have 2 kicker Comp VR 12's that were around $100 each which is probably less then one mopar 10" sub.
jaygotti, if you want dvd/nav and know a thing about computers you may want to look on this forum
www.mp3car.com everything you'd ever want to know about building a mobile entertainment system, or you can also buy premade head unit/ dvd systems that have a retractable screen. I just prefer to build my own stuff, for those electronically inclined, you can learn ALOT just by checking the forums at
www.carsound.com especially the fabrication section, many of the members are professional installers who do custom sounds systems for a living and also build competition show cars, they can be a gret help when you need answers and save you from wasting money on bad equipment