Help with a volunteer project I'm doing..

[Destin]

Alright guys here's the deal:

I'm working on a background image for a gospel tract (card with a gospel message on it). It's going to be handed out to mountain bikers at local races. I'm not trying to start a debate on religion here, so don't turn this into that.

Their idea for the image, is a mountain biker riding on singletrack (narrow trail) up to calvary (hill with 3 crosses on it). I have a vision in my head of what I want it to look like but don't know where to start.

Do I try to hunt down stock photos, and then edit elements from them together? (say.. find an image of a rider going up a hill, and add the crosses in PS)

Would doing this with stock photos present any legal issues? Am I allowed to edit them?

I'd go shoot the photo of the rider myself, but it's all snowy out for the next few months and they wanna print these in a few weeks.

Any input would be great. They said it doesn't even gotta be complex, it can be a cartoon (too bad I'm TERRIBLE at graphic design) I figure photos are the best way...