First thing i am not sue of, is it allowed to make a custom like button, like designing a custom badge in photoshop and use it instead of the standard button. Any tips on this?
I could not find anything about the styling. For a Like Box i found the older version using "fan" instead of "like-box".
Changing the facebook like button style is not allowed, as described in the brand permissions page (see section "Usage" of the like button).
Honestly, that doesn't surprise me.
If you still want to proceed, here is a custom like button generator. I did not test it, though (but you can see the html they use).