What I did when I went through all of that on my 180g I had 2 QT's set up. 1 For Fish, 1 For Coral. I had set them up way in advance though. No rock/sand in either, thats important. Put a Seachem ammonia badge in the Fish QT. Can just be like a 20L, which is what I used. Go to Home Depot/Lowes and get some like 2" PVC Couplers or Pipe and cut to size so the fish have somewhere to swim through and hide. Throw a decent filter and flow and heater on there and you are set. Can throw a cheap light on if you want if you don't have great ambient.What cycle method would you use for a QT?
I understand you are going like ALL out on this build. But on QT there isn't really anything to go all out on. Like seriously. Cause you don't want most of that stuff on there. Whole point of it is to get it cycled normally, I recommend Bio-Spira, then dose ammonia until it is cycled. Throw your new fish in there for 30-60 days, however long you feel is best. Mine was always 14-30 days. 14 if they showed no signs of anything and fed good. 30-60 if they showed Ich or anything else.
I personally did preventive treatments. They were always in Copper. I only dosed other meds as needed to treat w/e I found. I did all of this under the guidance of @Humblefish as I'm lucky enough to have been in his home state and he was only an hour from my house lol.
With all that being said, on this tank/build Im doing now. I'm not doing any of that. I plan on ich management. QT Process is safer and I highly recommend it, but I'm doing something different after tons of research. GL.