I seem to recall there being a standard half-giant template in a Dragon Mag, or maybe that was a half-ogre.
*hunts around a bit*
hmmm, I found half minotaur and half ogre, along with a bunch of other halves, but no half-giant. (Dragon 313, if anyone is interested.)
Secrets of Sarlona just references the EPH psionic half-giant, so that doesn't really help.
Any problem with just dropping the psionics and the editing the other abilities a bit, and maybe lose the LA? Could use the half minotaur and half ogre from the Dragon mag I mentioned as guidelines (maybe not as official as one could hope for, but still, at least it's something.)
There is one way... if you don't mind losing powerful build, you could take only the first level of the half-giant racial class listed in the complete psionic. Which incidentally also states that racial classes can be intermixed with standard classes (ie: you don't have to finish a racial class before taking other class levels). So, maybe a plus for those fond of applying the savage progressions concepts globally.