Log-in plugin

Hi everyone,

I’m searching for a plug-in that will allow me to have a simple log-in box for visitors, but I would like something that allows the user to either pay for membership and have access to all the downloadable content in the e-shop, or sign up for a free membership and not have access to the downloadable content. Does anyone know of a good log-in/registration plug-in that does this?

Thanks a lot.