i'm not so sure about the windows, but the photos shouldn't be too hard.
make sure all your photos are either in jpg or tga format.
make a folder called textures, then make a folder called inside called unimatrix and put your folders in the unimatrix folder.
go back up in your file browser till you see the texture folder, right click on it and select "create archive" and make a zip file. (if you are using windows then you'll have to do it in a different way).
you should now have a zip file containing a folder called textures, which contains a folder called unimatrix, which contains your photos.
now you need to rename the zip file to something that makes sense and ends with .pk3
so you could rename it to unimatrix-photos.pk3
now just put the pk3 into your tremulous/base folder and it should show up in gtkradiant next time you start it.
