Struggling on the GPS without an idea of the panel layout / budget. If it were my aircraft I would probably rip out the engine instruments and most of the flight instruments and fit an MGL Enigma, which would do everything and give an emergency blind flying option. Alternatively, my old 196 GPS and panel mount bracket would be ok at +6 –3G so you could go with one 296 and one 196 (same mount). I have a 196 for sale second hand if you are interested.
What is the aircraft?
Rod1