I am looking for a professional icon library for a financial software product.
Please advise me in finding right vendor.
You may want to include a little bit more information about what you're looking for, because I don't really understand. Do you want a site that has icons for you to use on your websites?
Go to iStock or Fotolia. Find an icon set that you like. Contact the artist to see if they will do a bespoke set for you.