Allowing an user to manage sites on a Multisite install (Moderator - like)

I'd like to allow an user to help me manage the sites on my network, but not making him super-admin.
He should be able to edit/delete sites, send e-mails to users, and that's it.
I tried the "User role editor" plugin, but it doesn't have the manage_blogs capability in the list..
Any solution? Can i just add manage_blogs and manage_network_users somewhere on the DB to give just this user those rights?