I think it's a great idea for a business. I also once tried to build a similar business, but then went in a different business direction. But I can give you a great tip to use the great font generator tool from actionfonts.com. Its main feature and advantage is that it is completely free. It's perfect for creating designs on t-shirts or other items. On this page, you can try the font from the iconic movie "Back to the Future" or download it on your computer. I hope this is exactly what you were looking for. Good luck!