Hourly Billing & Editable Invoices

I would love the ability to create services or bundles with an hourly rate rather than a flat fee, or by sqft. as I charge hourly for commercial properties and large homes (over 4,500 sq ft). Additionally, it would be incredibly helpful to be able to edit an order or add services or add-ons that are requested at the shoot, right up until the final delivery email is sent. This would allow me to open the original order, input the actual hours worked, add late requested add-ons and update the invoice with the final cost before the client receives it."