Well, I'm picky so I've just done them myself.
I like to share so I'm giving it to you. There are 9 big brushes - at lest 1300 px each, so you can use them also in printed stuff. Created in GIMP 2.2
You can find more hawksmont GIMP brushes on my blog
And now go into your folder with the downloaded brushes and place them via drag and drop into the brushes folder from gimp. After you started gimp new, the yhould be there.
sry for my stupid english
Then, click the "blank page" icon to create a new brush folder, and browse to find it. The rest is pretty easy, but reply if you still don't get it