At first: if you are going to hunt once you would rent a gun in Africa – if they will have suitable one for you.
At second: to be able to hunt safe you must be able to shoot twice in fast temp, consequently you need a proper stock. Mostly to achieve this a man need to restock his gun or optimize current gunstock. Buy, restock, sell – its not a dial. I think renting gun it’s a good idea for you, but its just my humble opinion.