You would want regular, the Blonde formula was spoke very little by Dr. Christopher, it is even hard to find. I don't think they ever even made the regular formula from what I have seen, he states he never had to look at his hair, so he didn't care if it was white.
Odds are you will not get the blonde formula anytime soon, there was only a gallon to begin with and will take some time to make again. The website ordered way more than I have ever had.
There is not much differance in the regular and blonde formula, the additional of one herb has an effect on the formula that makes it lighter and if allowed to age it does turn a shade of blonde. The formula does not dye the hair, you hardly even put any on the hair its self, so I am not sure why Dr. Christopher even suggested a Blonde formula, especially since hair was not a priority back then.