Sawzall through original resonator inlet: 2 minutes.
Cut replacement 18" pipe and add flange: 5 min. tops
Weld onto resonator: 5 minutes.
Add additional muffler hanger: 5 minutes
total time it took in a freind's driveway with a sawzall and a small welder: 30 minutes. And that's just with the rear on jackstands.
Tell the guy to use the pipe from your zetec exhaust and weld that onto the SVT exhaust at the resonator. They are the same diameter, and the Zetec pipe already has a muffler hanger in the correct spot in that area. That will save them having to make a flange and all that.
If he can't get this done in under 45 minutes, he's in the wrong business.
BTW, I had my previous exhaust, from resonator to tip bent, hung, and welded onto the car in under 10 minutes at a shop here. It's not hard when the car is lifted.

Good luck, man!