Database Creation Plugin to develop, enter, create, display data

Hi,

I have been working on a new site (WPMS 3.0.1) which main purpose is to provide information to the members of all communities inside it. However, the admins (property managers) are requesting an interface to manage monthly maintenance fees of all property owners. Specifically, to provide every neighbor (user) with an status of their property maintenance fee (payment date, paymentMethod, amount, balance, status: good standing, overdue, etc). Quite simple. In the backend the site admin will have a summary of all payments and the status of overdue accounts.

This is how it works:
The Super Admin creates the community(site).
Every community(site) have a property manager (admin) and lots of property owners/neighbors (users).

I need an interface/plugin so that the admin of every site could enter:
ownerId, paymentDate, paymentAmount, paymentMethod, currentBalance, Memo

So I also need a backend which is only accessible by the admin of every site and that every property owner/user might see their respective account balance information.

I need a DATABASE CREATION PLUGIN. Imaging a plugin that could allow you to develop almost any kind of database within wordpress... Nice huh!

Questions:
1) Does anyone know of a plugin that could do the job?
2) If 1 is negative, is this possible using several WPMU plugins combined?
3) Anyone knows of any other alternatives to do the job?

Any clues will be appreciated.

Thanks.