This is probably my most downloaded item. I had created a set of Easy Paint Tool Sai brushes.
You can download them here http://qtmelon.studiokemono.net/saibrushes/qtcustomsaibrushes.zip
To install the brushes, place the images in same folders I have them in. It's wherever you installed Sai. Then place the start-sai file in the same folder where the Sai.exe file is.
It should automatically update the brushes and create a backup as it starts up Sai.
I wish Weasyl had better ways of handling resoruces like Brush Sharing.