Create site with user generated information.

Hi!

I am looking for some help finding plugins.

I am goin to create a site where:

1. The users pay to become member (I have already found that plugin).

2. The users can buy stuff. Need plugin, have found some of them, seems pretty good.

3: I would like the members to NOT se the regular wordpress admin interface, I would like that to be customized by the theme. May find a plugin for this, but if you have a nice tecnique or plugin for this, please let me know.

4: And no for the stuff that I don’t have a clue about how to do:

I would like the users, through my customized user interface, update information, lets say the members are updating their body weight once a week or once a day.

Lets say the site has 100 members and each of them are uploading, to their profiles, their current body weight. And then I would like to display this information, for example through a diagram och graph through time. To display the graph itself isn’t a big problem since I have found some nice Javascripts for that, but the problem is to let the users fill in the information.

The users will also be able to look at each others profiles and see their weight graphs.

This will be like some kind of health community.

Does anyone know how to do this last thing i am looking for (item 4 in my list).

Thanks for your help

/Daniel