Dynamic DNS module idea

I'm creating a module to handle dynamic dns and bind administrative functions and I thought I'd put this out there in the hope that someone may have some ideas of the hurdles I'm going to come across. Here's a bit about the poject:

The goals are:
1) DNS Update Gateway Operation:
Allows the server running drupal to act as a gateway to update someones dns records using dynamic updates. The dns server is not neccessarily the drupal server but it could be.

2) Zone Administration:
Web interface to add and remove resource records from a zone. An administrative backend to allow modifications to all zones handled by the server and a user's front end to allow self serve to a user's own dns zone.

Appeal of drupal for this project:
User database and security system is already done and the separation of back-end and front-end functionality is useful also.

It seems like a relatively small project but no doubt it will be 3 times more consuming than I expect depending on how many features end up being implemented. My current ddns solution is in perl so to get things rolling the functions to add, remove and update dns records will just call the relative perl script but I have a view to using the pear Net::DNS to keep it all php so I'm allowing for this.

Some issues I see:
The module would add some tables to drupal and I'm not sure at this point how to make it work with the data abstraction layer. Are there docs about this somewhere - I have looked, there's so many (which is what I like about drupal coincidentally) a point in the right direction would really be appreciated.

Keeping the resource records up to date can be done using the dynamic updates but creating new zones will require write acces s to the conf file but I think this will be fine with a bit of a permissions checking script at install time for the module.

Let me know what do you think of this idea.