You might want to consider just running the coaxial speakers all the way around. Those Cadence drivers are pretty decent. Use the AC to all four of the coaxial speakers. Most of the time, the reason one runs duals (any) like this is for SPL or to keep up with super efficient bullet tweeters, and running single AC 4.300 isn’t what I would ever call an SPL amplifier, even bridged. In no scenario can I see running dual coaxial in a dual same location for anything other than SPL, just don’t consider it if you want good sound. IF you want to run mid or mid-bass duals, that’s fine, use the subsonic filter on the amp and let them roll off naturally. At 2 ohms overall (even when using a tweeter in the mix) you will have substantial output from this little amp up front and then the rears will produce good fill with the other two channels. You can set the gains for favorable fade then fine-tune with the HU. Assuming you go with the dual (non-coaxial) 6.5"rs and the tweeters, I would put the tweeter in the upper door, as you want to be as close as you can to the midbass drivers.
taking another look at that door, you might want to consider getting a nice 2 ohm 6x9 (using an adaptor for the 6x8 or 5x7 opening) comp set for the front like these:
Product Details: 6" x 9" V Series 2-way Component System Car Speakers Power Handling: Peak: 900 watts per set / 450 watts each side RMS: 300 watts per set / 150 watts each side Polypropylene cone material Nitrile Butadiene Rubber NBR speaker surround 1" Silk Dome Tweeters CEA-2031 compliant: Yes...
nvx.com
And a matching set of 2-ohm coaxials for the rear (or their 5.25" counterparts) like these:
https://nvx.com/collections/v-serie...mponent-speakers-with-25mm-silk-dome-tweeters
I think that watt for buck, this would be a better option than any of the aforementioned configurations and provide very good SQ with the added volume of having 2ohm output all around. ;_