Np problem Bird.
As for your questions regarding Sig Series from my understanding, artist are able to send their finished commissions of their work directly to CGC, but need to fill a special form for it, but thats only if their working on it from home. As for authorized witnesses I believe the term for them is known as CAWs, and you're not required to pay them. They get payed by CGC (very little like $50 a day). Facilitators on the other hand have prices that vary depending on who you get, and what sigs you want.Facilitators are good if you wants autographs, but can't make the show so you hire them instead. Since you'll actually be at the show I' would save the money, and just do the leg work myself, that is unless you want to go around the convention, and relax, than I would recommend paying the facilitators do the leg work.
For autographs yes you need to get a CAW to go with you to the artist. You can get one easily by just going to the CGC booth, and telling them you need an authorized witness to go with you to get a sig. They will then follow you to the artist, or writer you want to sign your book(s), and have them sign it in front of the witness.When done just walk back to the CGC booth with the witness, and fill out the paperwork. If its a sketch cover where the artist is drawing on a blank comic, you can actually drop off the blank for the artist to draw on, and only need a witness with you to pick it up when it done.
I hope these answer your questions, and if still confused, I recommend this thread in the sig part of the forum, which actually answers all your question much better than mine. http://boards.collectors-society.com/ubbthreads.php?ubb=showflat&Number=3777459#Post3777459
And here's a list of facilitators who are taking submissions, so you can see if any are going to the con you're interested in. http://boards.collectors-society.com/ubbthreads.php?ubb=postlist&Board=86