Super Smash Bros. 4 Model Project

[uac9000]

How do you handle UVW unwrap and render to texture for these models? I'm trying to render Shulks torso and head, it looks fine to start with. i apply the maps and they render nice and smooth, but when use UVW unwrap to flatten the textures it creates all kinds of seems, and i don't know how to fix this. I also noticed by default some coordinates like the torso unwrap are placed outside the checkerboard box in the unwrap modifier so that they will repeat and wrap around the model. But if they do this how will i get them to show up in render to texture without flatting them out and creating all those texture seams?