Talk to your retailer
If you let him/her know that you prefer dealing with the local store, but need to be certain of stock and timely availability, you might be able to work out a deal.
If you know your local store's ordering schedule, you could give enough notice so delays would be minimal.
If the you give your retailer a chance and make a reasonable demand, you might be surprized how reasonable the response might be. Even if you don't buy there in the future because it just didn't work out, you at least made the effort and have him/her the opportunity to beat out the mail order comptetion.