You could probably modify an encephalon to handle a great deal of that control. If it's taking over all your "mundane" processes like, not going slack jawed and drooly when you think real hard it stands to reason you could have it programmed to help you interpret and react to social stimulus appropriately while you plot the next phase of negotiation (ie you smile when you should instead of scowling behind you sunglasses like you normally do
. Hot wire a emotitoy into it? A blood circut control systems sounds like it'd go a long way to suppress the physiological response to fear or apprehension. Honestly a series of auto injectors with various hormones and a biomonitor would be able to accomplish quiet a lot. You could shut down fight or flight at will, dump some extra dopamine to even out your mood and so on. Probably have a bunch of preset triggers like "Don't freak out!" and "Show that that you're angry!".
Just some ideas.