E450 front speaker upgrade?

What's the "Best" way to improve the front cab speakers on an E-450? Space looks very limited, possibly necessitating use of the existing in-door speaker mounting locations???

1. Easiest would be to replace better quality 3-way speakers in the door; and add Dynamat and foam to deaden vibration. What size are the stock speakers? How hard is panel removal?

2. Next step up might be to install "Component" speakers, with mid-range in door and high frequency tweeters elsewhere (likely higher in door?).

3. Other "better" mounting locations, ideas or advice? Will be using high end components.

Thanks