Umm, Xephs maybe? From the XPH/psionics SRD?
They're medium-sized but have +2 Dex/-2 Str, darkvision 60 feet, +1 on saves against magic and psionics, a Burst ability to get a temporary boost to land speed a few times per day, and are naturally psionic so you could take the odd Psionic feat if you felt like it. Psionic focus could help out the occasional Concentration check when you have to be sure of getting a good roll (anyone with psionic focus can expend it to treat a Concentration check as though 'taking 15' similarly to taking 10).
Speed of Thought and Up the Walls could be interesting psionic feats to have (they function as long as you have psionic focus) for movement purposes. Could multiclass in Psion, Wilder, or Psychic Warrior, along with levels of Wizard, Bard, or Sorcerer, to enter the Cerebremancer prestige class at some point (arcane-psionic equivalent of mystic theurge). Would have to keep your non-PrC levels fairly even though since Xephs have Soulknife as their favored class, rather than an actual manifester or caster class.
Or perhaps Deep Halflings? Or I guess something from one of the Races of X books. I forget, are Spellscales (Races of the Dragon) or the like LA+0?