You don’t need to air down unless you’re rock climbing. It makes the tires softer so they can better conform to rock surfaces for better traction.
If you’re going to Tift (I think I read that you guys were somewhere) you really don’t need anything special. It’d be hard to get a stock vehicle really stuck there.
Anytime you go offroading though, you should have a first aid kit, tow straps, spare tire, hand tools, CB or cell phone, and a hi-lift jack is a wonderful tool (they cost about $50). Also, NEVER GO ALONE. Make sure a friend comes with you in another vehicle.
When you say you’re looking for a shop that sells offroading/mudding stuff, what exactly are you looking for?