Well, I have about 10 photo to comic actions that I got in my subscription at www.actionfx.com. Al Ward is a photoshop guru and he's the best when it comes to actions. It is a subscription site, though...i think he's got month to month and maybe even a 7 day subscription thats VERY reasonably priced. I think a whole years subscription is like $24, so its very cheap. There's tons of freebies there, too, so maybe you'll get lucky and find what you need for free. Plus, he'll probably be able to tell you which would work in gimp, and he'll make actions to order if you request them. I think the site has well over 100,000 actions/styles/brushes etc all included in your membership, and tons of those will work in gimp. You can also look into photoshop elements. Its WAY cheaper than photoshop. You can even get free PSE versions with lots of electronics purchases. I think i got one when i bought my Wacom Craft tablet, and another when i bought some antivirus, so its out there. If you just buy it, you can get a few year old version for about $40, I think. Just make sure you get PSE6 or higher, cause thats when they started being able to use many photoshop actions. Obviously, some don't work in PSE..that's the difference between a program thats under $100 and one thats close to $1000, but tons do. I'd check out AFX, send Al Ward a message, show him your sample (though you might want to cover nudity) and ask for his advice. He works really hard to meet client needs, so crossing fingers he can help you!

Good luck!