For 1st level, I'd seriously consider the wizard/cerebremancer I suggested above. Precocious Apprentice (Alter Self) + Arcane Mastery (or Versatile Spellcaster, if you go with sorcerer) with a useful race can let you get some decent combat ability, even at 1st level, and you can share this with your Psicrystal
and your Familiar. (You probably shouldn't risk the familiar, though, given its fragility and the penalty for its death. You probably want to check with your DM on just what happens if your psicrystal dies, also, and how you replace it.)
At 2nd level, you can pick up the Hammer power. Now normally this is a suboptimal choice, but if you choose an Alter Self form with a bunch of natural attacks, and also turn your psicrystal into something with a bunch of natural attacks, this could get nasty. Notice that Hammer is a swift action power, and that it "charges your attack". To me, it sounds like you could manifest this and then make all of your attacks as touch attacks that do 1d8 damage. Add on Knowledge Devotion, and it's even better.
Add on a bunch of
Sassone Leaf Residue (from Minor Creation), and this gets downright insane. Since your
type doesn't change with Alter Self, you should still have any racial poison immunity. So a warforged might be the best race for this. Make it a dragonborn to get rid of the stupid composite armor and for an even bigger boost to Con, and to pick up something nifty like a breath weapon or wings.
If your DM uses multiclass XP penalties, this build could be problematic.
Later on, this will turn into more of a typical "Big Guy" build. I'm just focusing on how to make it moderately effective in the early levels. You could leave off the warforged stuff and pick any other race you want, and just sit back and let the psicrystal do the fighting, also. It will take attacks of opportunity due to its lack of reach, but at 1st level most things still probably won't be able to hurt it due to its hardness.