If you go the Tiller Money route, @DFin, consider sharing any workflows, templates and insights you gain for others hoping to run a retail business out of a Tiller Money spreadsheet. As @Kathryn said, there is a long track record of success for small services business in Tiller Money spreadsheets— and the Simple Business Dashboard is a great addition.
I agree with @Kathryn that your business sounds like a fit but there will be a few problems to solve at the margins. Let us know how it goes.