Erin, our Wegman's has SF Irish Creme and a couple of other flavors at the coffee bar. They also sell the syrups, but they are expensive there and not always made with Splenda.
If you can't find SF syrups at Marshall's, try a local coffee shop. You can usually place an order with them and it's pretty inexpensive. Even if it's full price, it's still cheaper than paying shipping and handling.