I have been flying my Europa with Rotax 914 IFR for about 20 years. My approach is a little different.
Redundancy – how much do you need? Today’s radios do not fail like the ones from 30-40 years ago and even if a radio fails, the IFR system has a procedure to follow (squawk 7600 and follow your filed plan). I am content with my single GNC355 WAAS GPS/Com. Previously I had a GNS430 non WAAS/Com/Nav. I do use an iPad with FltPlnGO providing GPS course information. Some people carry a handheld com or gps/nav/com but my experience has been without a dedicated external antenna, com performance is poor.
Electrical capacity-Rotax electrical capacity is limited, a 914 or 912ULS (carbs) is a max of 20 amps, and realistically you shouldn’t plan for much over 15 amps. The first consideration is that the Ducatti regulator/rectifier suppled by Rotax has a history of failure due to poor construction and undersized heat sink. Replace the Ducatti with a B&C AVL-1 which has been specifically designed to solve these problems. My Europa with two GRT EFIS screens, GRT EIS, GNC355 GPS/Com, GMA240 audio panel, Appareo ESG Mode S ADSB out transponder, Stratux ADSB In receiver, LED strobe lights and one electric fuel pump consumes 8 amps in cruise. I am comfortable with this setup since I load check my EarthX battery every Condition Inspection to ensure it will deliver at least 10 amps for 60 minutes before falling below 12 volts. If I have an electrical failure, I have 60 minutes to land.
Pitot heat is not required per FAR 91.205. The newer Garmin and Dynon heated pitots cycle and reduce the power requirements to just 10 amps, so the Rotax system should be able to keep up. I have an old AN5814 pitot static tube which draws nearly 15 amps. I seldom power it on but should I need it, my battery provides the energy in excess of what the generating system can provide. While pitot airspeed is nice to have, we have GPS ground speed available which is good ballpark information. In my Europa I fly approaches and landing using pitch for airspeed control and power for rate of descent, so actual airspeed is nice to know but not required.
BTW, if you decide you need more electrical capacity, Monkworkz seems like a good choice. It will use the vacuum pump mount on a Rotax, but be sure your Rotax has the gear installed.
Hope this helps.
Jim Butcher