Small mids and tweeter amp help

[bjohn118]

Front speakers
Highs - Pair DD audio at-28a silk dome tweeters (50w rms s4), or I have a pair of DD audio vo-b3 bullet tweeters (50w rms s4) I could swap out to
Mids - Pair DD audio am-3a (50w rms s4)
Low mids - Pair DD audio aw-6.5a (75w rms s4)

 

Rear Deck

Mids - x2 DD audio vo-m6.5b (100w rms s4)

 

I have a rockford p600.4 running the rear deck and going to a DD audio crossover in the door for the 6.5s and the tweeters.

 

Gonna be changing out to the 6.5s listed above and adding the 3 inch speakers. I am considering adding another amp for the 3 inch speakers and tweeters and using the 600.4 only for the 6.5s and doing away with the crossover. I do plan on adding an audio control dsp as well. What are your thoughts and opinions, should i use a second amp for these or should i just use crossovers. My head unit also has a built in amp so there is a potential i could use the headunit to power the 3 inch speakers and the tweeters. Let me know what you think and your recommendations.