For our long-running campaign (still running!) we use a mixture of rules taken from: AD&D 2nd edition Psionics Handbook, the S&P Psionics Net Book, the D&D 3rd edition Psionics Handbook and the Mindscapes system.
I made one pathetic attempt to scribble the system down here:
http://www.twinmooncircus.net/psionics.htm
unfinished, of course, and now I cannot even understand my own notes... :/
However, I have some experience playing a thri-kreen in a humanoid 'clutch'. Is there anything in particular you are worried about?