You can't deactivated the PATS so don't bother trying.

You can buy blank remote key blades from Ford for about £4 and any key cutter (Timpsons) will cut it for around a five using your old key as a template for the keycode. Remote keys can be picked up on eBay for around a tenner and your newly cut keyblade is a straight fit. Yes your going to need to get the 2 keys and the car all coded to each other but Ford aren't the only option for this - I paid £50 to get mine plugged in and coded at a Ford specialist and I've since sorted myself out a Jag flip key and a re-bladed mk2 flip key giving me a total of 5 keys which all work the same car.

More than 1 way to skin a cat if you can be bothered researching it.