On a standard 55 gal. drum one grate is max. and it should be 7 1/2" below the barrel rim, ala BDS. Remember, you are cooking directly over the fire, there is nothing to buffer between it and the food. ONE air inlet, using a 3/4" ball valve to control air flow is all you need, it will rarely be open more than 1/2". The first one I built had more inlets, I found they were not needed. I personally use the "faux BDS" lid configuration. My choice is six 1" holes evenly spaced around the perimeter that are all open cooking and using the 1" metal plugs to close them after cooking.
Make sure your fire basket is raised above the bottom of the drum for air flow under it. I use carriage bolts 2 1/2" long through a piece of HEAVY expanded metal cut to fit inside the drum and build a separate fire basket with bottom.
Metal handles tend to get hot, but I use them because they are cheap and readily available. I just keep a pair of leather work gloves handy.
I use all stainless hardware.
What you do, or anyone else does, is strictly personal choice.
I'm telling you what I do and what works for me.
I LIKE my drums. And I HATE the "UDS" title. They are not ugly.
