New account, this one we will doing all quotes, billing and job costing ect for client.  They have several jobs already in progress, some billed some not.  For those I have not completed a quote/proposal since already in progress.  Two are complete that I am getting ready to invoice so they are my testers.  If all else fails I will provide a copy of what the company used before and just do a standard invoice lol!  So my question, concerns ect are what is the best method for doing this with progressive billing ect? 

Quote, Sale Order for progressive (can payments be applied to this?), then a final invoice once complete an apply all the sales orders?