Specific members plugin

Hello;

Does anyone know of a plugin that will allow me to do the following with my wp site:

– convert it into a paying site but only for certain articles.
– do not modify the look and feel of my site at all.
– if an article is premium content, a free member gets a message to become a member or log in to access the info.
– if a paying member accesses premium content and they are already logged in they simple get the article without any notice.
– if a paying member isn’t yet logged in when accessing premium content they are asked to login and will be automatically forwarded to the article. they do not to have to log in again to access other premium content.
– paying members also have access to all free content.

I checked all the members plugins offered under wp but none seems to do what I want.

any suggestions anyone?

Thanks.