[memphisindie]

Just like the example you posted, since you aren't attaching to the kingstuds, since there won't be any, the wall below is not load bearing and the truss is holding the building together. the wall below it will not hurt it. What you put on the wall will not matter as far as structural integrity. Do what you want.
I thought you were talking about the 2x4 studs in the ceiling if you were having a lower ceiling.
You would need to have a layer of rock on resiliant channel ad then a layer with green glue, then another rock sheet. Believe it or don't, but, wrapping the bldg. in plastic sheeting inside the studs will help stop through transmission and keep the plastic loose other than stuffing fiberglass in there, and 703 is just 7lb fiberglas panels, you can put them in there if you want but it seems like a pricey tactic to me when rolls of bagged insulation are much cheaper.