Single author page for multisite

Hey Everyone.

I have tried to google this but having a hard time explaining it in a way google understands, so time to ask here for help

Im running a multisite with different sections.
sectiona.site.com
sectionb.site.com etc

I have a few writers who can write a article on any of the sites,
However this is where it gets interesting.

Id like for each author to have a single profile eg
authors.site.com/user
and all the profile links redirect to this profile
I have managed to get the url to redirect using simple htaccess file
But now im trying to find a plugin or similar to take posts from all the sites and display them on the main profile.

I Hope this makes sense and someone can try help me?

Thanks
Tom