These suggestions may be off topic since I ran my car in an active configuration (5ch, no passive crossover). If I was going to do it again, I'd try a small, 2-3", full-range instead of a tweeter.
I used these 6.5s in my car. I am really happy with their sound and output.
https://www.madisoundspeakerstore.co...-magnet-4-ohm/
For the tweeters I used these:
https://www.madisoundspeakerstore.co...-dome-tweeter/
It might be worth thinking about going active for your setup because the OEM wiring pretty much requires you to run wire anyway. You can get a head unit like the Pioneer DEH-80PRS to do the crossover and EQ, just add amplifiers.