connecting to Multiple GSM Carriers


I plan to use MC7354 module here in Pakistan which is in South asian region.we have few gsm carriers available in my area.My question is which firmware image I should use to connect to a few GSM carriers? is it one image for one carrier or there is one generic gsm firmware that I can use to connect to multiple carriers ?
Please advise Thanks

Why are you going for the MC7354, this is for the US, MC7304 is the better unit to go for and there is a generic release for it.