How to question: custom email digest/newsletter across categories?

Hi, hoping someone here knows of a creative way to help me setup a feature I need.

I need to create a weekly digest email that sends (to users who request it) essentially a newsletter digest of the posts from a couple of categories from the previous week.

The first part of the digest needs to be the full text of the most recent post in the “summary” category from the blog.

The rest of the email should be a bulleted list of linked titles for every post either tagged “weekly” from specific categories or categorized by “weekly” from the blog.

The more formatting I can control the better.

Format in general that I’d prefer in the email

[Summary category: most recent post: title]
[Summary category: most recent post: full text]

[Category1]
* 1st title of post from Cat1 tagged as ‘weekly’ from past 7 days
* 2nd title of post from Cat1 tagged as ‘weekly’ from past 7 days
* 3rd title of post from Cat1 tagged as ‘weekly’ from past 7 days
* 4th title of post from Cat1 tagged as ‘weekly’ from past 7 days

[Category3]
* 1st title of post from Cat3 tagged as ‘weekly’ from past 7 days
* 2nd title of post from Cat3 tagged as ‘weekly’ from past 7 days

[Category7]
* 1st title of post from Cat7 tagged as ‘weekly’ from past 7 days
* 2nd title of post from Cat7 tagged as ‘weekly’ from past 7 days

Any ideas? The blog is behind a firewall to, so public tools like Feedburner can’t help.