I've used Illuminas on a non Miata before and liked them, I had AGXs and Tein springs on my Miata, I actually liked the AGXs but HATED the Teins. I'd also pass on the Blues.

I haven't read everything, are you set on a coilover sleeve or would you be interested in a good spring? A good shock/spring combo with a few other suspension bits can provide a very nice handling Miata. You just won't have ride height adjustability but...