Dialysis and Mamographic machines

We are about to bid for the supply, installation and maintenance of Dialysis and mamographic machines in various state government hospitals in Nigeria, We would want a supplier who who supply, instal, maintain and train technicians who would handle the machine. Payment shall be via a cash collateralized letter of credit from a reputable first class European or American bank that has a correspondent banking relationship with a Nigerian bank. In effect payment will be on a cash and carry basis. We  would also demand the normal warranty from the manufacturer and or supplier. We shall also require advise on the environment in which the machine shall be installed.