Focuser for a Celestron 80ED

I've looked for a way to more accurately focus this scope and I don't know how to mate a two speed focuser to this tube. Is there anything I can do with this scope? It's only a problem for me at higher magnification but I'd like to get the most I can from it. I'm not quite ready to spend the money on a expensive refractor. I don't think I know enough yet.

Well since I posted this I did acquire an AP 6". Not here yet but I still want to get a focuser for it. It looks like there may be a JMI focuser for it. Anyone know of anything to use with it?