we have a few commercial customers - nothing on a grand scale, mind. All I have is a henry, and the usual cleaning materials - polish, glass cleaner, hard surface cleaners. colour coded cloths etc- we use mostly evans vanodine prods as we tried them, and we like them and find them well priced.
don't forget insurance.
we sourced local suppliers through yell.com
we also provide a tailored cleaning specification for each customer, terms and conditions, and a quotation in writing after we have been to see them.
we never quote over the phone and we quote per job rather than per hour - as the guys on here had advised when I was starting up, and we have had no queries from customers by doing so - they think it makes sense!
hope this helps,
good luck!
ange