Shouldn't be that hard . . . all you need is to make a few monsters (easy with the monster-factory like section of d20M), a few extra Psionic powers, and another race (Protoss).
However, might I suggest a radical change? a new ability score, Psi, and a Psychic Hero base class to go with it. Not exactly sure how it would work, but it seems appropriate. Maybe Humans would need a feat to even have a Psi score, most monsters/zerg just plain wouldn't, and the Protoss would have one automatically? Seems a bit more appropriate than basing it off of another ability, since there are plenty of smart Terrans that aren't psychic at all.
Just my 0.02$,
Jeph