I am thinking about the following:

1) Getting the double din bezel from weedahoe
2) Install Pioneer AVIC-X930BT (or some similar double din Nav/BT unit)
3) Bypass the Infinity amp and have it wired directly to the 4 speakers in the doors using the Pioneer amp

This last step is the one I'm least confident about. I don't want to get into separate amps and woofers, etc. If I do this, will I have to replace the stock speakers with 3 way speakers? If so, what brand is the best bang for the buck? I realize I'll be losing the tweeters on the dash. Will I lose anything else? I'm open to better suggestions.

 

Frankly, the stock speakers are the weak point. Your best sound upgrade will come from high quality speakers.
My truck had the basic sound system, so I put a Kenwood head unit (Nav, iPod, bluetooth, DVD) a 4 channel Alpine amp and Infinity Kappa speakers in the stock locations in the doors (6x9s in the front, 6.5s in the rear doors. I also added a mono amp and a JL audio 10" sub in one of their custom fit boxes under the back seat. Truck looks completely stock, but it sounds better than my wife's new Mercedes. Way louder too

 

I am of the same thoughts about the stock spkrs as Super Dave.

I have a 10" JL 10W6 that was never used...5-1/4" JL's for the rear and 6-1/2" USA made MB Quart for the rear. Older MB Quart were made in the USA.

Can you PM me a link for the head unit please? Thats all that is left for me to acquire to complete mine. Thanks.

 

The most important thing you can do is scrap the factory speakers