Hi Roman,
I'm not sure where you are writing from, but I think finding an aluminum staff might be easiest online. I suppose you might try a large outlet home improvement store, but again, not sure where you are writing from.
@ Pete, wood is traditional, of course, in particular wax wood or a hardwood which slides in the hand nicely and takes impact over time. Training with metal, a heavier material, is a type of conditioning. So another example, doing leg raises wearing ankle weights, take off the weights, and whoa! feels so much easier, your legs move faster, your body is stronger. Same idea. Aluminum is useful because of the advantage of not chipping or denting like wood. I don't personally own a metal staff, but we have them at the school and we use them sometimes for wrist conditioning drills. Some more senior students can do a whole form with a heavier staff - impressive to watch
Cheers, Inga