OP has asked for "best bang for the buck", which would be to add two Dynon servos to the D100/D180 system that is already in the RV-7A. If in future the system is replaced with Skyview then the servos can be retained.
There are currently supply constraints with some brands and models of avionics, so that is another thing to consider.
Paul vS (yes I'm also a Van)
Building RV-6A #22320 O-320 FP. Wings and tail complete, fuselage almost done, working on canopy.
Flying my Aeroprakt A-22 STOL and the aero club's RV-9A while I build