Do a search here for template switcher...
This would be the preferred method for ZenCart...where you would have tem1, tem2, tem3 or name you prefer, copy all the template information and template overrides in all places....but use a different css file for each.
There was an older switcher that unfortunately does not work correctly with 1.3.x but the basics are the same. I believe that one has been created but has issues and has not been contributed as a result.
I can provide you with the "old" one to base off of if you email me at my addy in my profile.



