I have one of the prototype sets of springs for sale. PM me if you're interested.
Other than this set that's for sale, and the other set that's on a local Spec B, there will probably never be any others. We are still not planning on making these. Not because they didn't work out great, but because we are no longer planning on making springs at all due to them being a hassle.
We carry a lot of other brands if you'd like to get something else. But please don't hold out for Crucial springs.