What do I need to make my own brush?

Let's see...

-marine-grade epoxy
-hair knot
-handle



Anything else? I was thinking of getting a handle from Kim Son and then getting a knot from the Golden Nib. How dense or floppy are the knots from the Golden Nib?

depends on the grade of the hair, and how deep you set it in the handle. they are great knots, though, I've made several brushes with them, they've all done a super job

Sounds like you're off to a good start from here. Lots of folks like using the Golden Nib knots to restore old brushes, as well. Do you know what kind of material you want for a handle?

You can buy what Tony calls "UK" knots at the Golden Nib. They are more expensive, but made by Vulfix.