The rears are all 6 1/2" and any 6 1/2 inch will fit.
I had the Infinity but I am quite sure the others also had 6x9s in the front. They are shallow 6x9s, so not all will fit. If you ask someone like Crutchfield, they will tell you 5 1/4, maybe some 6 1/2, will fit as replacements for the front 6x9s. That isn't true. You CAN put several aftermarket 6x9 speakers in the front of our trucks without interference with the window mechanism. Not all, but most like Pioneer will fit. I definetly recommend the largest speaker you can fit in there. I was talked into 5 1/4 componants for the fronts. The factory 6x9 w/ factory tweeter on one side and the high-end 5 1/4 w/ tweeter hooked up on the other side showed the 6x9 to sound much deeper. The other had clearer highs but was over all no better since it was so small, but anyway.
For the door panels, get a trim removal tool from an auto parts store. They are on so strong that the tool alone will dent the door metal where the pry point is. Put a thin piece of flat metal (1/8" ?) under the leverage point of the trim lever to spread the load against your door metal. I put a shop towel under the metal piece to not scrap the paint too. When you put the door back on don't use all of the yellow Christmas trees, half of them will do. You'll have some extras and it makes it easier to remove the next time.
Hope all this jaw flappin' helps.