TrulyRazor, my apologies, I've never used either of these projects, but my guess would be - do you have a functioning sourcebans database that this can connect to, with admins in it?
From my understanding, this won't create new database/admins, it only adds bans to an already existing.
Someone more experienced can hopefully help.
Storm,
It's my understanding sourcebans won't run on Gmod, this only connects to a database created by sourcebans.
I'd experienced guestimate that the local Gmod bans file would still remain, as long as you didn't use the (2nd/replace) method from the first post.