sure. I use SAI for all the drawing. Then I use PS for some effects that SAI can't do. I love SAI. It's awesome how it works so good with my tablet.
as far as I know, there's no tools to download online... I create my own brushes or I take references around DA. You can find anything you need in here
I found a portable version with I installed in my computer. I can send it to you if you want, because it's really hard to find originals versions. I struggled pretty hard to find it.
If you want it, send me your e-mail via NOTE so that I can send it to you.