Shaun, No problem, any time.
I think if you are only having one color inside and one color outside you have it figured right. You will probably have a little left over if you don't sand it all off

. Better to have some left for touch-ups and repaires later than run short. The primer on the other hand I'm not sure about as I havn't started inside yet but I have about half a gallon left after doing the outside, however there is much more surface area inside than out. I like the idea of graphite on the bottom. If you have looked at my blog photos you'll see I have graphite on mine also.... you just can't see it

. I wish I had left it exposed. OH-WELL. It looks good though under the paint
I really like that System 3 primer. The crosslinker for the topcoat really makes a difference in hardness of the paint after cure. It's tough. Only 8 drops to the ounce, but wow it works good.
Forgive me but if you told me your colors I have forgotten.
Duke