Interesting project! My 150D also has the horizontal DG and a crappy AI. I'm waiting for the release of the Dynon STC to seriously look into replacing the AI for their EFIS, assuming I'll be able to afford it.

My priority is to get 04U safer for night flying and eventually for light IFR.

Victor
Cessna 177RG N1822Q
KHWO, South Florida
States where I have landed as a PIC
[Linked Image from visitedstatesmap.com]