I bought my own brushes at the time of my wedding. I am OCD about such stuff as well even though I know my MUA and am sure that she disinfects/cleans all her brushes. She told me what I needed and used those. I also took them back for the other wedding days I needed makeup done for.
Oh Shay, that makes me feel better already... What about products, did you buy what she recommended or did you use the MUA's makeup?