Reggie;
Sadly, I do not have a 12" blade planned. Since they are very expensive to prototype and hard to build, we plan only the major sizes. 4", 8", 11" and 16". I have a 5" blade, but there has been little interest in it.
If you are willing to pay the price, I can get one made with about 1 - 2 month lead time and a cost of about $800. This estimate and the estimate for the 11" blade come from exactly no data, only extrapolation from the existing prices and from our one-of-a-kind prototypes.
Just FYI, I shipped 4 of them today and it cost me over $40 due to the weight and insurance. At this rate and at the current list price, I will need to sell over 300 of the blades to just recoup my costs. Development is an expensive process.
PE