Do I really need fans? I will have vents and have been considering running a fogger.
on something sealed and viewed from the top, i would most definitely put fans in. otherwise, you'll be looking at condensation on the glass all day. the air circulation will help keep the glass clear.
very adventurous project. it should be really cool. at 12" of height, it's a bit low for most plants. especially after you factor in substrate and such. but there are a few mini's you may be able to keep.