I ended up using the spacers included with the Alpine speakers. I will try to take some pictures when I do the other side.
Depth is not a problem, the SPRs are tiny speakers. I was determined to use the factory brackets without too much modification due to the covers that protect the speaker from dripping water. With the spacers I only had to bevel the edge of the factory bracket to fit them in the holes. I am guessing the Bose trucks have a 5 1/4 rear speakers. I also didn't have tweeter holes in the front doors, but the door panels are marked from behind which made locating where to put my holes super easy.
The other thing I encountered, I dont know if it is with the Bose trucks or with all of them, but after using the spacers, which obviously pushed the speaker out some, the surround was VERY close to the opening in the door panel itself. So I ended up opening up the hole in the door panel itself to be sure that the surround didn't hit the door panel when playing.
My next plan is to have my old trusty speaker box recovered with tan carpet.