As far as naturals I would agree with Doorsch. BUT Based on what your intentions are re. using a SR sparingly, I would pick up a relatively inexpensive Barber Hone. There are many ( a Swaty for instance ) that will accomplish what you want to accomplish, and if you find one in good condition it will last a lifetime.

A good Barber Hone along with a good linen and leather strop ...and learning how to use them properly...would be all you would need. Millions of folks over many many years have done just that.