Hi,
-- Have you studied the IK sample from the mecanim wiki page? it shows how to control arms and legs via IK, and it's likely a good starting point for you to aim. I would not choose yet another asset to work this out, until you are very confident what how Mecanim works, as well as how PlayMaker interacts with Mecanim. Tho Final IK is PURE GOLD!!!!
-- To blend, I would need an actual working sample of that kind of system, if you find one, let me know, and I'll port it to PlayMaker.
Bye,
Jean