Rich,
The pot was just a plain pot (clay) just a very large one. I cut out the bottom of the pot and turned it upside down. As it had the rounded shoulder shape it was ideal.
Re the steel tandoor, I light it with a lit match dropped onto the burner when the gas is turned on. I then lower the baffle plate on its legs over the burner (stands about 3 inches clear of the burner). I have a kind of gripper tool that allows me to do this. I then use the same tool to lower the briquettes in a steel bowl onto the plate. To be honest if you didn't have the briquettes you could just stand the skewers on the baffle plate (you may notice the drilled dips in the plate for this purpose) and any juices that drip onto the plate will smoke and burn giving you the smokiness associated with tandoor cooking.
Whatever you make, you are correct, you will need to let air in. The steel one has holes in the bottom sheet steel. This is ok as there is no debris/ash to worry about. The charcoal clay one only had the one airway which was big enough take out the leftover ash when cooled. This hole allowed plenty of air in to feed the fire, at times I had to restrict the airflow using bricks as the air would get sucked in at such a rate the charcoal would burn very quickly.
I can tell you, that conventional clay tandoors (charcoal) never go out in a working kitchen. As home user we use ours just like a bbq. The only problem you have is when you first fire it up you get a layer of soot that sticks to the sides of the tandoor. You have to wait until the tandoor gets hot enough to burn this off. You don't want to try and slap a naan on that. When it is hot enough to burn off the soot you cannot hold your hand over the opening let alone put your arm in to stick a naan on. So you have to wait for the temperature to drop somewhat which means the fire is starting to die back. This is where a lot of babysitting is needed trying to maintain a good cooking temperature.
I prefer my gas one totally and will not go back to trying to cook using the charcoal.
Just my thoughts on the matter.
cheers,
Mick