Category-Specific Subscription (Subscribe2?)

Here’s what I’m looking for:

A monthly e-mail feed based on a simple registration form that allows users to decide which category they wish to follow. Since I use categories for brands, there’s only three possible categories to follow.

I don’t allow comments, so the form has to be as simple as:

[x] Brand 1
[x] Brand 2
[x] Brand 3

[email protected]

I want a plain-text e-mail to be generated with post titles and their permalinks and an unsubscribe option at the bottom.

Now I’m looking at Subscribe2, but this plug-in won’t allow monthly newsletter updates. It also introduces the problem of non-registered and registered users… registered users will have the options I want, but I only want one kind of user.

Subscribe2 also feels like overkill for what I’m doing.