As far as I know all Quest labs send their c3a/c4a draws to Mayo, who then forwards them to National Jewish. You might be able to save a few bucks by shopping around though. It takes 4-6 weeks to get the results back, they are getting pretty busy these days it seems.
Im thinking the best way to find info on acat would be to study acetylation and then figure out the places that enzyme functions. Sounds arduous, I havent even even started down that path yet.