
I looked into this, and decided it's just not worth it!
Ceramic bearings (particularly full ceramics) really come into their own at high RPMs (ie 1000s), which you'll never achieve on a bike, and certainly not achieve in a pivot. Part of the advantage is that the material is harder than the grit, so the spinning burnishes the race, that won't happen as the pivot bearings don't rotate enough, so save your money!
You can get some Finish Line 'Ceramic Grease' which claims to have a similar effect. I was cynical, but it's revived my very notchy headset bearings, so it may improve bearing life.