Don't forget the mundane - do a careful count of the number of serial ports you'll need, bearing in mind that they are paired(both input and output of a pair run at the same speed). If there is a 430w in your future you'll want to display the cdi on your efis, saving the $2K cost of a garmin cdi. That requires an ARINC input. I think that costs you $500 and a serial port on the sport and HS, but is included on the HX. Serial lines to/from autopilot, gps, transponder, engine instruments, remote magnetometer (and ADHRS on HS or HX), second EFIS, .... They all add up. I went with an HX and HS pair, and ended up using 7of the serial ports on the HX.
When time comes for a backup electric AI I think you'll find a Dynon D6 or a TT ADI (I forget the name of the new unit) to be both less expensive and more reliable than a mechanical AI.