Amigakit, Vesalia, AmigaStore and Amiga shop all have various 9 pin Dsub joystick and joypads for sale depending on your preference.
You can also use USB sticks and pads with the Rys MkII adapter which is available at most Amiga hardware dealers.
Full info on the Rys MkII is available here.
http://retro.7-bit.pl/?lang=en&go=projekty&name=rys_mkii
