Tiny spaces like converted wardrobes or grow boxes rule out most strains straight away. Plants need to stay short, finish quickly and tolerate the heat that builds up near the light in an enclosed cabinet. Compact indica leaning autos listed at https://budweedseeds.com (ttps://budweedseeds.com) were the only ones I seriously considered for a forty centimetre wide cupboard. Honestly, airflow turned out to be a harder problem to solve than strain choice in that kind of setup.