from what I found out building the corsa the Vectra b, astra g, zafira a, and vx220 share the same ecu. only difference is the base map to suit the car.
think astra and zafira are the same but don't quote me on that. so long as you get an ecu for a manual astra with transponder and chip you should be ok.
fit second ecu and send your original to be sc mapped.
