I use hungarian agates to cut cabochons as well, the first cab what i did cut was a small round stone, i used 220SiC grinding wheel for it.
The surface was ugly, low quality polish on it. Than i stop cut cabochons but after few years when i bought some professional diamond wheel i started again to make cabs.
Now i cut normal round and oval cabs and unique shapes too. I use my cabs for belt buckle, bolo tie, jewelleries and sell them to wire wrap and other customers.