We suggest that until you have both a signed agreement and some money, you should keep the Order as a Proposal. Then, and only when you have both, you can simply change the Order Status to Confirmed.
In RW Elephant, you get to change the Order Status from Proposal to Confirmed manually so you can always insure you have both agreement to your Terms and a deposit before making the switch.
If you use Integrated Credit Card Processing within RW Elephant and send your customer an Online Payment Page, they will agree to your Terms and make their deposit at the same time. In that case, the Order will automatically change from Proposal to Confirmed.