Just a short comment on the tent. Would Jade be able to use a shelf unit if she used the tent turned on its side? Seems with 24-inches to work with, vertical space might be a little tight in the tent. If she went with flat panel lights I can see that she'd have room for a single shelf which would create two levels...the bar top and the shelf. Wouldn't more than one shelf be too many? Maybe just a section of closet shelving sitting on a couple of supports at the ends? When you're talking about a six-inch tall pot and four-inch tall plant the actual plant/pot height starts eating up the height...especially if you need some adjustment room for the light's height. Jade, measure your bar's width to be sure you have 24+ inches for the tent to sit on...you might as well measure the height between the bar top and whatever is above it. It would work better vertically, but they work turned on the side, too. Andy's throwing a good deal out there to you, just do some homework and make sure it'll fit the space that you have available and that you can utilize it like you would want to.
As for the dropped down ceiling over the bar... Possibly future cabinets were planned for the dropped down area. Or, possibly for what you said...pictures, decorations, or maybe for lights to be mounted beneath it to illuminate the bar top. The old trailer that I have my plants in has a bar in the "great room" that divides the kitchen area from the living room area. It has cabinets above the bar which takes up a lot of the vertical space but I'm not sure how much. Get that measurement from bar to ceiling...sometimes our eyeballing things can be off a bit.
And if it seems the tent isn't a good fit you could consider simply mounting lights directly beneath the drop-ceiling over the bar. As for humidity levels...those can be worked with humidity domes and plastic sheeting strategically hung from the edges of the drop-ceiling.
I can't remember... Are you wanting to grow *all* of your plants indoors 24/7/365? Or, is this just for germination and seedling/leaf-cutting propagation?