Database structure - which one is better?

[eluser]Bonyc[/eluser]
Everything working good so far. I have added the DX_Auth and I have created 3 user groups:

1. Member
2. Moderator
3. Admin

** There will be another group of users who will be Guest to my website and who can view some of the data provided by both Members as well as Moderators (eg. in the form of their profile pages).

I would like to achieve the following:
1. Members and Moderators can create one profile page (something like www.mydomain.com/username) with some about 30 fields / 20 fields respectively in it.
2. Moderators can view the profile pages of all Members and can contact them.
2. Admin has full control over all the data submitted.

Please guide me to achieve this if someone has already work on a similar project. If you know of any good information source that will be of help for me, please do leave by a link.

Thanks for all the support
Bonyc