I am considering a small 4 channel amp to run my 4ohm door speakers and possibly my old 5 1/4 (4ohm aftermarket) door speakers that I put in the hatch area, or should I run the sail panel 6 1/2 woofers? Whats the best setup to run off the 4 channel amp if its even a good Idea.

Also my car was not a Monsoon system car, but I bought a Monsoon Head Unit out of a 02' TA and put it in my 95' TA.

 

I really recommend against using an aftermarket amp on the stock speakers....

 

They're aftermarket speakers. The 6 1/2"s in the door are Alpine's and Im moving the Kenwood 5 1/4" speakers that were in the doors to the hatch area, so the only thing stock are the 6 1/2" subs in the backseat sail panels and the tweeters.

 

I'd run the front doors and rear subs off the amp. The 5 1/4"s off the headunit..... actually I wouldn't even put them in there....

And yes, you can connect your amp to the stock headunit. Using any line output converter.