We needed a camera port. Checked in on putting one in our "C"
model. A factory one would be a geat expense so we put a 2"X4" hole in the belly and got a 337 field approval for it . Works great. The glass for a pressurized plane would be about $15000 just for the glass. If you want a big hole I would buy a plane with the port hole in it.
Erlend