OK, just so that we are clear, here is the typical scenario. I don't think it is as simple as it sounds:
Caller dials 703-555-1000 (DID);
Without it being answered, it is forwarded to a cell phone (as if they had telco *72 forwarding);
The calling number displayed on the cell phone is 703-555-1000.
Also, remember that we are seeking something comparably-priced to a Vodavi STSe which prices thousand$ below the IPO.