Depends on the pose, but if your planning on doing crawling, it doesn't matter. On striking poses, the first half of the snake gets tubed, and the rest is belly cut to the vent with the tail tubed.
but given the shrinkage of the skin (not sure if snakes skin shrinks) I know supergluing the ventral cut together is not hard but concerned on lining up the belly scales right...
Snake skin does just the opposite. It stretches.
I staple the belly skin and lining the belly scales up is actually pretty easy.