Yep, all the hotels have gift shops with some convenience store-type products. In addition to that 7-11, just a little further south is a Walgreen's, and across the street from that is a CVS. Now, granted, a lot of the merchandise is tourist-oriented - but they do also have typical merchandise, as well.
Also, there's a pretty new Walgreen's about a mile, maybe a little less, down East Flamingo near the intersection of Paradise road - less touristy.
Are you going to have a car?