So I received my charger yesterday and it does plug right into my power supply from MRC.
So here is the power supply if anyone is interested,
http://www.amainhobbies.com/product_...C-Power-Supply
I think if I were to do this again I would have just bought another MRC Super Brain 989, right now they are on sale for $110 at amainhobbies and that comes with an external balancer and power supply.
http://www.amainhobbies.com/product_...RB126-Balancer
So when you look at the price of the Hobbyking parts,
$33 plus shipping
$42 power supply
$10-20 for balancer plug leads and temp sensor
So that is roughly $95-$100 and for $120 I could of have one that comes as a full package deal. I guess the cheapest charger isn't always the cheapest solution.
Nick