Do a search for rotary joystick; there have been a few good threads talking about this lately. Ikari Warriors used a mechanical rotary, so you would most likely prefer one of those for that game. You will need an encoder that can handle that type of stick. Both Ultimarc and GGG carry them. The optical rotaries (I am pretty sure) hook up like a spinner. For either, you still need to hook the joystick microswitches to an encoder as well.
If you are going to order either of these, check the BST forum. Some of our members sell them cheaper than Happ.