A 1000 watt light is perfect for *two* C22s, if you hadn't considered that. You don't put the door on one, and you put a better backing on it, then stick them together, the one with the backing in the back, the one with the door in the front. That's a bit less than 16 square feet, which is just about perfect for a 1k light. A few people I saw on overgrow did it that way. I think one of them called his 'The Monolith'. Not exactly stealthy though.

And I like cooltubes, but that's probably just a matter of personal preference. Tubes take up very little space, which is why I like them, especially inside a cabinet.