Well, after calling my petco and doing some internet research I discovered the following;
Each Petco store, depending on its' location (regionally) and what the manager wants, orders from the same wholesalers as any LFS does including but not limited to: Quality marine, Sustainable Aquatics, Apet, A & M, ORA, and, on the east coast special orders often come from Segrest Farms.
Also, when ORA is "overstocked" they do a "push" and ship out large quantities to Petcos to clear out stock.