I got lucky and found a pair of '67 rust free doors in excellent shape no one else wanted because they had 6x9 ovals cut in the door.... for cheap! Saved me from having to ruin perfectly good doors
Hey, if GM offered a stereo system that's where they would have put them.
I also bought a pair of '72 scroll door panels someone had installed 6 1/2s in for next to nothing...with speakers for dirt cheap. I'll just set my originals off to the side for if and when being purely original matters. I like good sounding music.
I'll probably just go 3-way, but if I go component the speakers in dash would be a good idea. I had a nice '72 door for sale at a swap meet with one rust spot in the lower rear corner (for cheap). Guys would look at the inside and say if it wasn't for the speaker hole they would have taken it. I don't get that. No worries over the rust repair required but curse that bedeviled speaker hole that would be so much easier to repair. Holes on the dash would be easy to fix... on a restoration.