I think you will have to create sections for navigation, head and content frame, and give all sections a pagelayout.tpl to control the layout of each frame.
I've been thinking about making a site with frames, but it haven't come to that yet. (Haven't been forced) I'd be grateful if you'd post how you solve it if you decide to go for frames.
We recently built a set that required the use of an iframe. Essentially the iframe (or frame) loads in its own space so you need to careful to ensure each frame has the right url for the task.
There are a couple of tricky bits. Communicating between each frame so that ez knows what is going on is pretty much impossible without using some kind of cookie/javascript combination. At least thats the approach we took for our problem.
The other thing to consider is ez will eat a lot of resources displaying your pages, one httpd resource for each frame you create: ez can only return one page at a time.
