Hm, so obviously they're sexually mature, but are they full grown? Syrian hamsters are generally not communal. They live solitary lives, males and females only see each other when they mate. You may end up having problems with housing them together.
I got a dwarf hamster awhile ago that was pregnant already and she had her litter shortly after I brought her home. I left her alone for awhile because I read that dwarf hamsters are very sensitive about letting you handle their young. By the time the babies were old enough for me to handle them they already had pretty thick hair. My snakes didn't want anything to do with them.
If your snakes are big enough for rat pups I think that's the way to go.