Thoughts on CMS integration?

I am building a small/medium sized ecomm site that will be managed through a little Rails CMS I have built. I've built a few CMSs in PHP in the past... In those projects the CMS would always live in its own directory and the public site in its own. Of course the two would share the same DB, but their source code would be logically separated into the front and back end.

Would this be the best way to do this in Rails as well?

I would prefer to separate the front end and back end, but I just want others input on this and perhaps a good way to handle it. Having both aspects of the project all in same app seems kinda messy, but I am not that clear on how to share a database between two apps, especially since it would seem that duplicate models would have to be in both the front and back end apps.

Thanks

Any thoughts on this guys?

Also just to clarify, Both the front end and back end would be Rails. I'm just wondering if putting both sets of functionality into the same app

IE

$ rails front_end_and_back_end

Is the best way to go?

Thanks