Custom Template and setting them issues?

[Fysez]

It's a lttle difficult for me to explain,
But bare with me:P

I've been creating my own style of a body template.
And currently, I've been having trouble making it so that:
Other than re-Gani'ing every body I make for every gani possible,
How would I go about having a folder, For example: levels/body2/*
and in all Gani's, replace the current body with my custom,
Yet the design changes to the uploaded body.

Sorry, It sounds hard to follow.
But for another example,
The current body template is changeable when you set another body and goes for any template with that body template.

How would I go about making something like this?