I would advise going against getting yourself listed with Chameleon etc - although I don't run a TGP, I know from friends that do that if you are not careful you will find yourself buried in shitty galleries.
My suggestion - start with some FHGs from a sponsor of your choice, and advertise on the boards for trusted submitters. There are always lots of submitters keen to get started - I'm a submitter and will always take a partner account where I can get one
Oh and good luck !