I did the AUG several years back (I left town for safer pastures). The original Atlantis store was in Athens, so you should check to see if that store is open. I recommend paying the extra at a store and pay in cash to avoid the paper trail (billing and shipping) associated with mail order. Think about how you are going to get to and from the store (friends car...rental car in friends name). Buy everything at once or get all supplies in bulk as to not be making frequent trips to the store. However, if you must mail order, do not order to your address or do not use your CC when ordering (do not drive your car when going to a store). I also recommend going straight for the 1000 watt light(s) with the air cooled hoods too. I recommend because I know you will never be satisfied with a 400. If you go ahead and air cool you lamp you will eliminate biggest problem of growing indoors - Temperature Control. It will be worth it in the long run trust me. Does not matter about your medium so much. As long the nutrients are right, the temps are good, and plenty of CO2, your crop will be nice. If you do grow in soil, use a good pro-mix and add some extra perlite (5/2 ~ soil/perlite)to allow good drainage. You need to master how to take cuttings to root and how to keep mother plants healthy. You will eventually need to get your timing right with your cuttings to always a have plants ready to flower when it is harvest time. This way you never have empty space in your flower room.
As for the market being wide open, be careful. Aug has a pretty long history of growers and a reputation for a place with way above avg herbs. It is open now because most of the growers got busted or got wise (got out of town). Alot of real shady stuff went down not too long ago in that market. Aug is a town with a lot of talk and plenty of people of questionable trustworthy-ness (both downtown and Columbia county). If you are thinking of meeting someone you meet on this site, you are insane. I would not trust my mother with my show. I surely am not going to go meet someone I have been chating with online. Obviously, you should be worried about the cops, but you should also be worried about people robbing you. The things you need to know about "the business" side of things are things you don't want to have to learn the "hard way". These things can leave you empty handed right when it is harvest time and/or leave you sitting in prison. When it comes to taking cuttings from other people, you should be aware you also get any bug problems they are have like spider mites. The name of the game is to be self sufficient when it comes to everything (especially genetics).
Resist the urge to want people to know you have a show.
Good luck!!