Program for Auto Repair Shop

I am looking for a program that can help me manage my auto repair shop's processes more effectively. Specifically, I need it to include invoicing support, so that I can send invoices to my customers swiftly and in an organized manner. I am not sure if it needs to be compatible with existing software, so please provide recommendations for the best options. Additionally, I have a specific budget in mind for this project, so please ensure that your proposals include clear cost estimates. With this program, I hope to improve the efficiency and effectiveness of my auto repair shop. Thank you.