The front doors are crossed over at 90Hz, for a low mid-bass threshold.
All your OEM speakers are 2 ohm, 75 watts.
Take a look at some 6x9 mid-bass speakers that fit these specs. These will be tuned to give you the frequency response you are looking for.
The biggest factor in upgrading the front door speakers is to ensure that they seat properly and seal.
I'm not one to suggest components (because audio is so subjective), but I can give you some pointers and data.
Hope this helps