rahh

I am in the market for a new stereo system for my 2004 Tundra Quad Cab.
It currently has the factory am/fm/cd with 6 speakers.
This is a system I am interested in.
Alpine "$1K Car Audio System"
I would consider any good brand name system.

The problem is this. The front speakers have a depth of 1.576 inches & the back have a depth of 1.36 inches.
I cannot find a brand of speaker @ crutchfield, bestbuy, circuitcity etc. that will fit in the factory openings.
I am a first time Toyota owner & not very familar with how they are put together. I would like to know if anyone has changed their system in the 04 Tundra Quad & if they know where I can purchase high quality speakers to fit the factory openings.
Also if the speakers are not avalable why is there a limited depth in the speaker location & can I modify the depth.
I would like to use the original factory speaker location if @ all possible.

Rahh