I ordered these LED bulbs from modbargains.com and decided to stick with what I've got. Check out the details on their website using the link below. These are plug and play for the fiesta with the use of the resistors so you don't get any error warnings. They're $140 with the resistors, but I'll sell them for $120 with free shipping with the continental U.S.
http://www.modbargains.com/gp-thunder-h11-cree-30w-led-fog-lights-fiesta-focus-e92.htm
http://www.modbargains.com/gp-thunder-h11-cree-30w-led-fog-lights-fiesta-focus-e92.htm