I used Intuit QuickBooks when I did catering work.
When creating a detailed proposal for the customer, it would turn the proposal into an invoice which could be edited if needed. Deposits would go in and a statement of balance due would be created, all while keeping detailed books and tax collection records.
It also had an inventory module if you elect to use it. It calculates cost vs sales and maintains a record of profit by each job and in cumulative numbers.
Humphrey's DownEast Beast W/BBQ Guru