The GTN750 is on my list as wells it’s such a powerful tool, I know I’m never using it to the full.
I’d go the other way and start with the avionics suite you’re most likely to fly regularly. For IFR, repetition helps more than starting with the least convenient box first. If the Vision Jet is already on your shortlist, learning the G3000 there is actually a pretty friendly way to build the habits, then moving to Proline later won’t feel like starting from zero. The main thing is to pick one suite and stay with it for a while instead of bouncing between three at once.