open up that area and take a look there,,, there is quite a bit of room and some custom speakers would fit nicely in there,,,
I dynamated my whole interior... including getting dynamat in behind the rear speaker areas and up the back to the rear window.. then the whole roof was done in aluminum bubble insulation/foam rubber under the headliner... it really helped quiet the truck ,, alot,,, and if you are doing stereo stuff I am sure you would find a huge benefit from the labor and expense,,,, I did 3 complete layers... 4 from the front seat forward... cost about 250.00 to do it
Obviously.. depending on your tastes an amp (s) would help fill the void with cleaner sound
I also noted when I was putting in a new dash that the open space in the center was huge and probably would have fit a subwoofer speaker... perhaps a visit to the expert stereo guys is in order... just for ideas.... truckin magazine is a good source...lots of gen 2 trucks usually featured (2wd) for dash ideas...
I think I would resist cutting any holes in the doors unless you can do a full hidden install and make it look sano stock,,, they always look mickey rat otherwise