Some mices were sold for ST and Amiga but I think there was a contactor to select the mode. You can't use a PC mouse directly, you have to connect it to the serial port and use a small program in your auto folder (this won't work for games).
Another solution is to use the keyboard :
Alt+Arrows to move the mouse (use the shift + Alt + arrows for slow move : 1 pixel).
The buttons are emulated by Alt + insert And Alt + 'the key at the right of the Up arrow'
RE: Which mouse? 
