I like your setup. Been thinking about something similar. I happen to have a spare 22.5 middle ring and a 4 22.5 ketttles, 3 of which are OTGs.....so 1 of them could get tuned into a high heat WSM. I was thinking of making new heavy duty legs to support the thing though. As per brisket - double heavy duty foil it with some stock at about 160-165f, cook it till the buger probes like hot butter the towel wrap till the internal hits about 170f and eat. I have had success with wrapping in brown paper (my version of butchers paper) but the moistest success has been with the foil.