aluminum vs. steel in brake disc
something I want to point out is that anodizing, even so called "hard" anodizing, is only a surface treatment, it is only a couple thousanths of an inch thick at most. after it wears away, you are back to base metal again. Therefore you need to consider how much wear you are going to experience per race and re-anodize after each rotor turning (assuming you attempt to remachine the rotors at all instead of chucking them in the scrap bin.). And the surface hardness is around 70HRC, therefore friction is going to be pretty low. once you get down to base metal, you are gounig to gall at least as bad, if not worse than the Titanium ones. (this is true of the coated Ti rotors too)
Anodizing also reduces the thermal conductivity quite a bit, aluminum oxide is a thermal insulator. Granted, again it is a thin layer, but it has to be taken into account.
Metal Matrix Composites (MMC's) may also be obtained from Coorstek in Golden Colorado (yes, it is a subsidiary of coors brewing....). they are mostly aluminum oxide, therefore their thermal conductivity will be pretty low, but higher than pure Alumina. St Gobain Ceramics may also be able to help.