Thanks for the tips. I'll keep my eyes open for when they post the artist listings and see who is going. Really looking forward to this one.Since you already know what you want, it would be best if you contact the artist you want to get a commision from first (once they release the list of artists attending of course). That way you can find out if they are going to be taking commissions and also how much they are going to charge.
Otherwise I would show up to the artist section first on Friday morning and get on someone's commission list early! At Celebration Anaheim, all of the artist were pretty much booked for the entire convention by the end of the first day!