It would be a bit tight for a perpetual harvest op., but plenty of room to grow one or two at a time. That would give you an oz. or so every 4-6 months once you got your technique down.

It would be possible, I suppose to section off a shelf on the top of about 16" for a clone and veg. chamber, but it would be a bit tight. Younger plants don't really need all that much space normally. Also, if you choose to go that route you will want to use low heat lighting such as LEDs or CFLs, and make sure you have some good ventilation.

Make sure if you do a top, or bottom for that matter, veg. chamber that you seal all cracks and crevices so you have zero light penetration to the flower chamber.

Whatever you choose, good luck on the grow my friend!