Hello, I hope I can be of assistance.
What do the garage say is causing the concern? Did they tell you the codes stored in the ECU, if so what are they?
Let me know and I'll reply as soon as I'm able to.
Sorry garage did not tell me anything other than it will need a new ABS system
as just the ESP light is on and not the ABS light and the garage says you need a new ABS system this would suggest that there is a fault in the ABS HCU with the brake pressure sensor. Unfortunately unlike some of the other Ford models the HCU isn't available as a separate part from the ABS ECU so is very expensive.
Personally I would try to source a used part such as at http://www.ebay.co.uk/itm/FORD-FIESTA-MK-6-55-09-FUSION-ABS-MODULE-AND-PUMP-4S612M110CC-4S61-12M110-CC-/310840854124?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item485f8f066c as long as the part numbers match then it is a straight forward replacement and no programming of the ECU is required.
Ideally before going to the expense of replacing the module assembly I would confirm the fault code stored putting the light on, most Fiesta and Fusion ABS faults at this age when a module failure tended to put the ABS and ESP light on plus give concerns with the speedometer not working.
Let me know if I can assist further and I'll reply as soon as I can.