I'd call ford and get a quote on the ecu edit before committing.. They can be hefty if they waste time. If the figure starts getting above $300 (shouldn't be more than $100) then you may as well spend the extra and get a flash box..
I doubt it'll take them long, but they'll charge by the hour, and if they don't know what they're doing you'll pay thru the nose.. Ask to speak to the workshop supervisor, not just the pleb that answers the phone and trys to sell up the fees and processes.. If the supervisor sounds like he knows what he's doing, you're onto a winner, this could vary dealership to dealership..

Cheers,
MaTTe