Would a guitar speaker cabinet be glaringly out-of-place? These are cheap, and you can eBay the individual speakers (and pretty much recoup your cost) and replace them with plywood baffles. You can mount your ducting to the baffles. All mods are reversible if desired. :thumbsup: If you leave a small speaker in there the cab can also be "functional" if that helps the stealth of the operation.

If you flower in there you need any ducts to be light traps. This subtracts from your growing space. And the more heat you've got, the bigger those ducts have got to be to move your heat out. (More lost interior area.) And with HPS, you can't let the plants get TOO close, so more lost area there.

100 watts of mixed 2' T5HO and CFL is about the most I've seen work in a really small case. Active intake and exhaust, 4" lightproof ducting. Some sativas can do surprisingly well--you can train them to grow all around your light sources.

Haven't seen it yet, but LED's would rule in these applications because of the low heat, small size, and close working distance to the lights. But I'm prejudiced!

Oh, yeah. With the small amount of action you've got going there, a small homemade scrubber on the outside of your cab, just nearby, should control smell problems. Least that's what I heard! :hippy: