oh I meant to write something about the hole drilling.
I looked for a step bit that went as big as 1" holes and actually did not find one. Apparently that is hard to find. But I decide to try the 1" hole bit.. however I chose one that also has inside of it a regular drill bit that acts like a pilot for the larger cut.
It worked perfectly and was $20 compared to step bit which would be about twice as much.
After drilling with the 1" hole saw with the pilot in it, the 3/4" iron nipples fit perfectly and snug. I then tightened a conduit nut on the inside and another on the outside as far as it goes and it's totally fine. The 3/4" iron nipples actually bulge in the middle and it creates a perfect fit. No need to solder or anything weird like that.
In other news!! I found this great site from Poland with lots of cool info on smoking in general, with some cool baffle ideas for smokers that look like drums: