I have all the parts, the design in my head, and the only reason I have not built this is b/c I have a 968, but - excluding the price of a heatgun, it should be under 25 bucks to make.
Basically the idea is to direct heat from the heatgun to both the bga and the underside simultaneously, and control the airflow speed w/o modifying the heatgun in any way.
I have just lacked the initiative, so if you want me to build one, test it, and put up pics, start egging me on.... lol
Hey Deary, got a heat gun? this may be for you, seeing how you're looking into a reflow station.....