No, I wouldn't expect to you buy a Mac just for that. I just couldn't remember if you had one, and if you had, whether you'd explored the relationship between the two versions.
The Mac iWorks templates look like files, until you open the packages. This is true of a lot of seemingly simple files on the iMac. I'm thinking the only difference on the iPad is that it does not include the ability to see the template/packages as files. That makes me think there must be an overall package standard that Apple uses, and that somewhere in the deep dark abyss of developer documentation that standard should be explained.
Not that it is necessarily readable by simple souls like me, or useful to your project. Just a thought that may or may not help.
Anyway, if you want I'll see if I can extract and PM you an OS X version of a templates folder structure. I've already discovered they can be imported on the iPad just like a regular pages document, so there has to be some kind of compatibility going on.