Honestly bigfot, I'd not bother with the Heiney. Go have a look
at what I use for the shangri-la 3:
http://bofh.ucs.ualberta.ca/beck/pictures/hothexnow for something like under your tarp, you may want a little more stove than my little piece of 6 inch pipe - rather than the little heiny keg, I'd use a piece of 8 inch round duct with end caps - do it 12 to 18 inches long. the longer stove will be easier to feed since of course you can put more wood in.
also depends how much you want it to weigh.
To vent it you can either use 3 inch duct pipe, or buy a rollup pipe from Titanium Goat (that's what I did).
With your tarp, what I'd also do is vent it out one end, use a sheet of aluminum flashing as a stove boot - I'd set up the tarp down low, get a good angle on the ends how they come together, and cut the flashing to fit - epoxy some velcro on the edges to match the tarp end, and then the boot just goes into the gap between the ends on the tarp. (Thought about
doing the same myself actually.
Just make sure when you buy galvanized pieces you burn them off outside - the initial reaction of the galvinized coating is toxic. once it's heated up and reacts and changes color it's fine.
