Doug,
I just thought about that this morning that I forgot to go over which one I use. I use the "Ultra Fine" as I want it to look as close to a true silver as possible without the flake showing. I haven't tried Super Silver.
I buy all of my HOK unmixed. I don't know if TCP carries them, but I buy from Coast their empty plastic bottles with the flip top and mix my own as I need it. I buy white by the quart and reducer by the gallon. I haven't figured it out, but logic says I am saving a bit by mixing it myself.
HOK has revamped their web site and you can find all kinds of cool formulas to get zillions of different colors. It's like a kid in a candy store, except their candy is real expensive.
http://www.houseofkolor.com/homepage/