I have actually done this (success is still pending but I'm alive SO FAR) with a Factotum 3/Psion 17 build. I'm behind on the powers, but I have an extreme Int focus, so I'm SADariffic. The factotum helps me start out the skillmonkey business, giving me all skills to choose from. I think it's humans with... Able Learner, that lets you keep all those skills as class skills (not such, I had a homebrew feat for a similar effect and I'm not human). Practiced Manifester is a must, of course.
Basically I have all the power of a psion, short a few levels, with the ability to perform nice tricks like adding +3 to my skill checks or (more importantly) my Int score to my AC or attack. The 2+Int matters less since most of my skill points will be coming from my juicy Int score, and I spend the extra points I got from Factotum on those skills that are trained only or strange. You should be able to lower the number of factotum levels, depending if you want Int to AC or not, could up your survivability. What with the armor prof. you gain and shields and the lack of ASF with psionics, good deal.
With psion you'll have plenty of powers as well so you can burn some on utility powers which your skills can't do. Oh, and of course you're not limited to straight psion either... your biggest problem is making sure your class skills stay class skills when you go psion.
Does this help?