I installed a set of infinity kappa 6x9's in the front doors of a 2004 RAM 1500 and 6 1/2 kappa's in the rear speaker holes.. Rears did fit with a bit of trimming but the system sounds rockin and cant even tell theyre installed. This truck had the Infinity system, i just wired the tweeters in the dash to the front door speakers and called it golden. Make sure to unplug the factory amp if you are installing an amp/deck..

800watt 4channel amp powering the kappa 63.9I/693.9I speakers
400 watt monblock Class D amp powering a 10" sealed boxed off brand subwoofer.
Custom wiring/install of the stereo, XM, and IPOD adapter

 

Become friends with your local sound shop. Don't go to the best buys and walmarts, they sell the low end of a brands series (such as buying the rockford fosgate punch series at best buy but then you can get the power and pro series from a reputable shop for not much more money). If you can turn a screw and learn how to solder, you can install a simple stereo system. Mine I did myself, and it is all new from the deck back, wires to the speakers and all. Buy yourself a good head unit (the stereo part) and go from their. Next update the speakers (my sound guy recommends rounds vs ovals since the rounds reproduce sound better), then go with the amp and sub, then a 4 channel amp for the doors, then you can just keep going from there. Once you get into it, and doing the work yourself, you are just going to want it louder and crisper... it gets addicting... all of this truck stuff does.

 

I think the 08 factory head unit with 6 disc changer, MP3, Sirius, and U-connect sound pretty good for a stock unit since it has the 3 band EQ. Not top of the line, but pretty good for stock and is much less apt to get stolen.

 

Frank james and some others hit it on the head. You could TRY changing out the speakers as long as you know in the back of your mind that you'll do the head unit down the road. MY though is you'll do that much sooner than you think as you'll be overall dissapointed with your results.

Best bet, go to a local audio shop and ask for a good head unti, very good amp, and install component speakers, with decent sub. You may have to do this in stages as the cost mey be between $2K and $3K. However, the cheapest thing to do would be to make a plan and build it as you can. Otherwise you'll just end up spending more money over time.

Building sound systems is a hobby of mine and not a job I've just learned the hard way by spending more upgrading then just putting in what I would like in the begining.

DO IT IN STAGES! It takes longer, but well worth it!

GOOD LUCK!

 

Lots of typo's and mispellings above...not enough coffee yet