Looks awesome dude. The mars 300 isn't very intense so I think it will work out well in that space. I looked at some strains and a few pop out at me for you.
Northern light
Super bud (greenhouse seeds)
White dwarf (Buddha seeds)
Betty boo (the joint doctor)
Night shade (Barney's farm)
Lowryder
All short strains. Anything indica dominant with a fast flower Time will work awesome for that space
Northern light
Super bud (greenhouse seeds)
White dwarf (Buddha seeds)
Betty boo (the joint doctor)
Night shade (Barney's farm)
Lowryder
All short strains. Anything indica dominant with a fast flower Time will work awesome for that space