Question about my idea...

Hello guys!

I'm working on an idea I had some months ago.

I have a WPMU+BP installation running, the BP site is the mais site of the WPMU network. In this network I have 9 different woocommerce sites running, with different SEO configuration, 'cause I´m selling different things on each site. All the sites are domain mapped. So, each site can be searched in google and atract different users to each store, but when a user wants to buy some product obviously the user must register on the site that sells the product.
What I want is that when the user goes to the register page, the user get redirected to the BP site and register and create a Profile there, 'cause I don´t want the user to register a lot of times, I want the basic information of the user on the mais site (the BP site), so the user just need to provide the aditional information to buy some product, such as delivery adress, credit card, etc. But the basic information such as name, e-mail and other things doesnt need to be informed again. So, basically, I want that user register on the BP site, "NEVER" on the subsite, in fact I don´t want they to register in each site at all! Just provide aditional information.

Is there a way to do it?