Hey does anyone know what a Sanctioned Psyker Brand looks like? I always figured it looked like the aquillia with the eye over it like they put on the Primus Psycher model from GW. Does anyone know of a description of it, or a picture?

This question keeps popping up a lot, but I'm afraid there's no real answer to it yet.

You could do it like you suggested. Alternatively, give the character in question the seal of the Adeptus Astra Telepathica: http://wh40k.lexicanum.com/mediawiki/images/e/e1/Adeptus_Astra_Telepathica_Symbol.jpg