Other then from my chipper friends, I only have one, which was a gift from Ross Poppel. It's from Greg Raymer.

I'd love to get some others.

As for what pen to use, I'm prtetty sure the "Sharpie" is still the standard. I would get a fine tip for more definition. If not a fine point, then no bigger then a medium point!

Use a color that is in contrast to the color of the chip. It's pretty hard to see a black autograph on a navy blue chip!

gOOD LUCK. iF YOU CAN GET TWO....i'D LOVE TO BUY THE OTHER FROM YOU!