Well, it sounds good to me.
Add the whole cans to your recipe, add the water to 1 gallon, add sugar to an S.G. of 1.080-1.090, all your other ingredients, and add the yeast, and then let 'er rip.....
The K-meta could pose some problems, so I would start a yeast starter, adding a little bit of your must to it bit by bit. I have never had problems with additives, but maybe I"m lucky. I think it sounds like a great wine already!!!
Oh yes, and let us know how it turns out!