I would not expect Van's to spend any time on making changes to the legacy RV-12 to try and turn it into an RV-12 iS. So far there are no legacy kit parts for the new fuel tank, electric flaps, or console mounted throttle to name a few iS only features. There is nothing stopping you from making the changes yourself and most have already been done if you look back at older threads.
All leather, comfort foam seats: Call Abby and order a set, I have had mine for 10-years. Same for side panels with leather arm rests.
Wing mounted heated pitot: Check the RV-12 threads, several examples of how to do it.
Parking brake: Easy to add on your own.
Aux alternator: buy one from Rotax and install it.
It's OK to fabricate your own parts and install them (after you get your ELSA SAWC).