Its funny, cause I am like you, I had drove by there a million times. Then the day came way back where I searched and searched with no luck finding barrels, I couldn't remember for the life of me where I had seen the sign.
Right now I can't remember the guys name but he is a heck of a nice guy. I ask about the honor system, picking up barrels and leaving the money. He said he may loose one a year if even that.
If you need the step bits for the air holes, watch harbor freight for a week or two. They seem to go on sale every so often for as little as 9 bucks for two bits. People can say what they want about cheep tools but I can't see spending 30 to 80 bucks on 1 step bit. Maybe if I made a living with it but I'm not even sure then.
I welded my air fittings and also my pegs for shelves. Then I read about the electric conduit lock nuts. Sure wish I had read that one first.
I have some pretty freaking cool brackets that I found at work that where heading to the trash. Just a little work with the grinder and they will be fabulous for holding the weber style grates. Drill one hole in them and bolt them right to the drum.
You are more then welcome to have enough for your build.
If you have trouble or need help finding parts shoot me a PM.