You're talking about spending big money on a smoker, Plan9.
Seems like [MENTION=16]Playmaker[/MENTION] had a fancy set up. It's been awhile since the BBQ thread was kicking.
I learned how to smoke on a 22" Weber grill, but have recently purchased an offset barrel grill from Home Depot. It was a cheapy in BBQ'ers terms, but expensive to me at $300. I've found that it doesn't hold the heat as well as the Weber. On the Weber I could smoke a brisket for 15+ hours with less than a bag of charcoal and wood. With the bigger grill it takes much more. Part of the reason for that, I'm sure, is that it isn't nearly as air tight as a high dollar smoker would be.
So my advice would be to find a product that is as air-tight as possible. That way you can dictate the heat and airflow using just the two vents.