I think the height scares some people (20 longs are only 12" tall)...I find that to be interesting as I stocked 2 angels in a 20 long for quite sometime with no issues including breeding. I also had housed them in a 20H at one point. I am curious as to your reasoning.
see above
Please if you would esplain I would appreciate it.
I probably wouldn't go smaller than 30 gallons other than for breeding. I've seen angels breed regularly in 10 gallons...