I use most of the suppliers I have used for other companies.
You can Google for local suppliers. Type in produce and places will pop up. Then contact a sales agent.They will send you order guides with prices.
Other professionals will be willing to help. Contact local restaurants and see who they use- not the chains, but local places. Look in the yellow pages for wholesale fruit and veg vendors. Try Sysco and US Foods- both are nationwide, I believe.