That is a great idea, be the bulk grain and hops distributor. You can probably even buy bulk specialty grains and sell them off in 1 or 5 lb increments.
I like my local shop because of all the great advice I get there. Now that I've been brewing for 3 years I'm more interested in price. My local also has an internet site and wil ship out orders, but I don't know what percent of their business that represents.
The idea of combining with another beer related retail shop is good as long as you still have time to answer questions that homebrewer will have.