My stack is flush mounted with the top but i made a piece of pipe i can put in from the bottom if i want to drop the level of it (i never have-it works fine the way it is). As you can see from the pix, mine is also a reverse flow.
I did not put a damper on mine. I guess they would be good-i didn't do it and dont have any problems now that i have learned how to use it. Once you have used a smoker a few times, you kinda learn the tricks on how much wood , when to put it on, how often etc. I did put a stack damper on mine which stays open about 3/4 all the time. Like i said, It's all in learning the nature of your smoker. Since you are building it yourself, you will have to learn what works on your smoker. My air intakes usually are wide open when i load wood in, but once it gets going good, i usually crank those back too. The first few times i used it, i took extensive notes on times, temps, number of sticks of wood added at a time, adjustments made to stack damper and air intakes and the effects it had on the temps etc etc. It really helped at first to learn when and what to do. I don't need to do that anymore since i have become more familiar with the beast. The last couple o time's i've smoked, i actually began using charcoal too, then adding wood occasionally for flavor. This seems to work better for me and it is a whole lot less labor intensve. I load the fire-box tray up with charcoal and light the very back edge and let it slowly burn it's way towards the front, adding a few sticks of hickory as it goes for flavor. One load of charcoal went for nearly 6 hours last smoke, then i finished up with seasoned hickory.
here's a couple o pix of mine.
be sure and keep us posted with pix of your build and your first smoke! we dig that kind of thing!