Multisite Wordpress

Hi Guys,

I have my WP-Multisite install setup and so far, everything looks good. I'm able to manually setup other sites, and interact with them.

Like other users here, I too would like to set up an Etsy-like network so that subscribers can buy and sell items, using Paypal chained payments so I can collect a fee.

What is not clear to me yet, is how to take the next step and make the network have a registration page page for new users so they can set up a new store automatically (again, working on the Etsy layout) once they are registered. I have installed the Marketpress plugin, plus added the Framemarket theme and the Gridmarket child theme on top of it. Are there any other plugins needed to make this work?

Any guidance you could give would be greatly appreciated!