I probably wouldn't go with monk/psion if you want a combat-intensive character. You're not going to have the attack bonus or hit points to hold up in a fight very effectively. I've found that Monk1/Psychic Warrior X works pretty well. You can get an obscene AC fairly easily, but you won't be hitting terribly often until you get fairly well advanced. Once you've got Claws of the Bear, Combat Prescience, and Deep Impact, things get a lot easier, but it's a rough time until then.
At fourth level, a decent monk/psychic warrior might look like this.
Human Monk1/Psychic Warrior 3
Stat Priority: Dex (as high as possible), Str (13+ at least, for Power Attack), Wis, Con, Int/Cha
BAB +2, Base Saves Fort +5, Ref +3, Will +3, hp 3d8+8+(4xCon modifier)
Feats
Human - Pretty open to your choice. I'd probably take Dodge, as a high AC is very nice. Inner Strength might be good, too - once you get Unaviodable Strike, you'll burn through power points very quickly. YMMV.
Character 1 - Inertial Armor
Psychic Warrior 1 - Psionic Fist
Monk 1 - If you can, switch Stunning Fist out for Power Attack. This is a rule from OA, and it greatly improves the flexibility of monks. There's a short list of feats in OA that you can do this with, all of them associated with martial arts styles.
C3 - Weapon Finesse (Unarmed)
PsW 2 - If you couldn't switch out Stunning Fist, take Power Attack. If you could, you've got lots of choices. I'd probably get Speed of Thought, or Inner Strength again, if you're finding yourself too low on power points and you took it at 1st.
You'll want to take Unavoidable Strike at 6th level, probably with your Psychic Warrior bonus feat. Using it will spend most of your power points, but it's a very nice shot at whoever you're attacking.
Powers (3/1)
0th level - Burst, Talons, (something)
1st level - Vigor (according to the PsiHB errata, this is supposed to be 3 temp hp/manifester level, not just 3, to a max of 18. That makes it REALLY useful - by the time you get it, it's 9 hit points for one power point.)
You'll want to pick up Biofeedback, Combat Precognition, and Claws of the Bear next, in roughly that order. Biofeedback and Combat Precog can be switched, depending on your faith in your healers.
That help any?