Which licence?

I’ve been wanting to start an open source art project for awhile now but the most confusing aspect of all of this is which licence to choose! I’ve already discovered that the GNU GPL doesn’t really cover art, and since I have stumbled upon three different licences that I could choose. Before I reveal them here’s what I intend to do:

I want to allow people to upload their original ideas onto a website and have those open for modification, whilst still crediting the original, and all subsequent authors/editors. Once an image is created I want the image itself to be available for modification and the original file i.e. the psd, xcf, svg etc file also available. All of these would remain free and not be allowed to be used for commercial work.

I thought Creative Commons Attribution-Non-Commercial-Share Alike 2.0 would do the trick but it doesn’t mention source files. I then came across the Free Art License 1.3, which seems to cover most things but there hasn’t been widespread adoption of it since early 2000’s so I’m questioning the validity of it. Finally I’ve come to the Open Art Source Licence, which is still in the draft stages but is more up to date, so possibly addresses more issues.

Can anyone provide any input?

Open Source

I’m going to be moving into exclusively using open source software to create artwork in the near future*. More on why once I get my head around some of the software.

*that is unless it’s completely necessary that I use a piece of commercial software e.g. GMIP doesn’t support CMYK, yet Photoshop does.