Hi
it depends. If you just want a few with no matching in colour, size and quality then purchasing from a single named farm is one viable alternative. But if you want matched and/or and sort of quantity then you will have to go to a wholesaler or retailer, both of whom have enough stocks to do the matching you then want.
It is the same situation as seeing pearl retailers who claim to buy 'direct from the farm' This is true once in a blue moon but generally one farm does not produce enough of one sort of pearl to produce something useful - hence they go to a pearl factory or wholesaler for processing, matching and drilling etc.( I remember seeing this claim from an on-line seller re freshwaters in China. She was posed with a hank of whites (so clearly no) in a lbd and spike heels.)