Paul at www.Technozen-electronics.co.uk has a very good reputation, the only thing to worry about is your carrier.
Alternatively buy a complete ECU/alarm/fob package and get it shipped to technozen so he can get you a second fob. Then sell your old set to cover some of your costs.
Home to black Alfa Romeo 159 3.2 V6 Q4 ,green MGF VVC and red MG Maestro T16.
MG - the friendly marque.