Just a single PM inquiry probably won't hurt, but I would recommend contacting Adam first (although his PM box is full) because BR's still working on his and will be giving priority to his personal suit before considering serving as an armorer for others. If we keep pestering him, I doubt he'll feel so much inclined.
Sean Bradley does some kickass helms as well, and Ben Streeper's are good as well. I think Adam also has a helm he can do that matches the rest of his armor. You could even get a kit from Westerf!eld and assemble and paint it yourself.
Adam's armor is good, but if you're really interested in buying these, I'd suggest making a "WTB: Full Mjolnir Armor or Body and Helm Separate" thread in the classifieds.