The 6.5" will fit in the doors, but you will need to cut out around 1cm Around the Door skin, to get them to fit in well.
The 6" fit straight in, no problems, no changes, and no extra holes needed for the Mounting Screws.
Also, the Speakers have 12dB Crossovers for both the tweeter, and Mid Range Driver.
Yeah, these speakers are not very Bassy, but having said that, Sometimes bassy speakers in the Door trims cause too many rattles, and tend to be a bit more of a headache to get good sounds from.
Price for these speakers is somewhat exy, but I was very pleased with the quality of em when I got em !
Hope this helps