Finding sourcing leads is the easiest thing in the world when dealing in wholesale.
Forget Google and wholesale lists, after all the lists are made up from businesses mostly sourced through search engine findings anyway, research you can do yourself!
Work out the product you want to sell, then call their head office and contact their sales and distribution department.
90% of the time they will be happy to explain their distribution structure and channels, and can put you in touch with a supplier based on the amount of units you want to purchase.
It's not rocket science, just a phone call, you get the right advice and you save yourself a lot of wasted time on the PC!