Music arrangements for viola, violin, cello, and french horn quartet?

I ran across a website that sold arrangements for the quartet consisting of the instruments above. I however, failed to bookmark the page and am now having a very unsuccessful time locating it. I need a website, company, or reliable program that will allow me access to music for such a quartet because I am in one and we need new music. I am at a loss of what to do and any help would be appreciated. Thank you!