Now the hard part, iStock only allows one upload of a release. SO I had to figure out how to combine them in Photoshop. What I did was combine them as a contact sheet. I'm not sure if that is how everyone else does it, but that is how I got all the releases into one jpeg. (they only allow jpeg)
To do this, I followed this path File->Automate->Contact Sheet II and here is what my settings looked like for 2 (change the columns field for more):
