Multi-grain flour

A lot of big box stores like Walmart Supertarget, Costoco, Roundy's, Publix,etc have either King Arthur whole wheat flour or Dakota Maid whole wheat flour. Gold Medal also sells whole wheat. These are just whole wheat and not "multigrain". Other flours can usually be purchased in the same store and you can mix whatever you want.

If you want to order online, the cost of shipping can be prohibitive.

Google on Bob's Red Mill and see if there is a store that carries their products near you.  I did a quick check and found them in NC, GA and SC.  Very good flours, (not cheap).  I use King Arthur for my basic bread flour when I run out of a really great bread flour I bring back from Waterloo, ON, Canada when visiting our son.  Any time you can buy in a store it is much less expensive that shipping cost via the internet.  (Just got back with a 20 KG bag from Canada and some stone ground whole rye too.)

Amazon.com has some multi grain flours, mostly smaller packages but does have some 25# bags of multi grain flours and blends. Since these flours don't behave like the usual suspects in baking goods aisle, you might consider buying smaller packages at first.