The main reason doors get cut up is that you want to replace the 8" with something better that isn't the same depth or has greater excursion.
I recommend doing a little research on speakers of similar depth and excursion before talking to an audio guy. You may love the sound of Brand X's 8", but it's just not going to fit stock. Go in with your absolute musts and some ideas, but be open to options that you never thought about.
I used some RF 8" in the doors. They are deeper than stock. But I removed the magnet covers, then used a heat gun on the inside of the chamber where the speaker sits. Using the gun, I heated the chanber up and while still hot pushed the speakers in to "mold" the shape. I did this several times and the spaeker literally fits like a glove.
2005 GT, Flowmaster, SCT, JLT CAI, Eibach, Baer, FRPP Struts / Dampers, FRPP Deletes, FRPP 4.10's, TA Girdle, BBK UDP's, J&M Upper Link/Lower Control Arms, FRPP GT 500 Front Control Arms, Hurst short throw, Foose / BFG FDW's