[morgal48]

With the Haes amp you will not get much out of your new speakers. The 6X40 has an internal low pass filter, so nothing but bass will be sent to the doors. Having been where you are, I found limited choices:

Replace the Haes amp and use any speakers that will fit the doors
Modify the Haes amp
Buy replacement factory speakers and keep the amp
Replace both the amp and speakers

My choice was a new amp and replacement factory door speakers. My ears are tin, but I have been surprised at the level and quality of sound from those 5-1/4" subs. And the fronts and rears (the paper cones in those died and were replaced long ago).

There a several posts here about the options - make sure those Alpines are shallow enough to fit.

Good luck