i have kickstart 1.3 and just found out incase nobody knows that you can use megadrive control pads.
It's known that you can use them. However there was a scare story going around in the 90's that because of differences between the amiga and megadrive controller ports, you shouldn't use them without an adapter (two of the wires need to be swapped).
Supposedly if you press one of the other fire buttons (the working fire button I think is B??) then it can take out the joystick port. I don't know whether I believe it or not, but I used an adapter as it allows software to use all the buttons.