petrol stations have 95ron, i'd stay away from supermarkets as its generally poor fuel, your best of just sticking with shell as the vpower here is 99ron. There are some esso stations that do 97 but subarus tend to like the shell stuff better,
not to sure which subaru tuners run cobb, i know the gtr owners have used it before syvecs became readily available here.
Have a look at race dynamix, duncan knows his stuff and has experience with various software,
Unfortunately another well respected tuner has recently passed who was down your neck of the woods