I have been doing my own digging. I do not have an iDrive screen. So, I am only looking at options that add a screen.
There is a new Pioneer model:
AVH-3400NEX. It looks like the screen will be able to deploy and just miss the gear shift. However, when deployed the screen sits atop the 1-DIN unit and will definitely make the AC controls difficult to get to.
The Alpine unit you are looking at is a 2-DIN unit and will not fit. However, they have a very impressive new unit that will fit:
Halo9 iLX-F309. It has an absolutely massive 9" screen. However, the screen is only 6" tall and comes on a floating swivel mount that allows you to adjust the height. I think you could adjust it lower so that the AC controls are accessible as well as the buttons for the retractable top. My only question is whether the screen comes out so far that it might obstruct the gear shift. (I have a manual.) The other problem is that it is pricey.