have you thought about an internal set up like on the Bibler and the "new" black diamond tents? I would imagine that this would save a lot on the construction and weight of the sleeves. you just might have to think of a way to tension the inside as the fabric stretches over time... or pick a fabric that wont stretch as much. i know bibler uses epic and they last a long time, so i assume that it doesnt stretch that much... just my 2 cents.
~Shaun T. KG6TNB tech. redwood city CA