Sounds a lot like my approach, so I approve!
What are the airspace requirements for those subs? The door enclosures are approx .14ft^3 (3.96L) from my research.
I went with more of a midwoofer for my doors. (I wanted a simple 2 way) I used the Dayton RS150P-4A, and they are just about perfect for the enclosure volume.
https://www.parts-express.com/dayton-audio-rs150p-4a-6-reference-paper-woofer-4-ohm--295-563
In the dash I only have a tweeter. I may think about doubling up on the tweeters in the future so I can cross them over lower. (I have a thing for arrays)
I have a build thread on diymobileaudio.com that I don't update very often.
2002 Porsche Boxster S - Car Audio | DiyMobileAudio.com | Car Stereo Forum
Best of luck!