Hey, I have the same JBL GTO930 6x9 speakers and I noticed they're def on the bigger side when it comes to proper fitment. How'd you get yours to fit? I ordered 1/4" spacers but those still aren't enough. They're installed currently but the bass is severely lacking because of the gap left from the speaker being big.3.5" with spacers is about the max total height - unless you start cutting your door panel / window mount apart. Not much room to play with on the back side, but you have about an extra inch you can move toward the door panel grill with. I've got JBL GTO930's in at 3.66" and it is slightly flexing the panel grill, but is secure.
Not sure on OEM amplified, but on base 4 ohm dash is way too bright and completely saturates the mids in the doors, based on how they are ran parallel with door - unless you put physical inline resistors to lower the wattage.
Not sure if its the same on OEM amplified -... but just found out the hard way after PAC updated their details on these after I already purchased that exact harness kit from ebay... that our Jeep Cherokee's don't play nicely with it. I ended up just running speedwire and tapping into high level inputs. I gotta look into Alfaobd now and see how much help that might be.