Garage Studio Advice needed = 23.5' x 29' x 8'

Hi Folks, I have a non-attached (to my house) garage space that is 23.5' x 29' x 8'. It is currently insulated and drywalled (not taped or finished dry wall though) to those dimensions. It has a partical board ceiling in at just under 8'. There are two aluminum garage doors and a rear door and small window. The garage has its own electric and breaker box and gas pipe and thermostat. I have to install a new furnace though (I live in Detroit area). I want to build a single combination control room and tracking room inside that space. I am planning to build an inner room for the project studio. I would like to keep it to 19 x 23 x 8 and use the front 10' x 23' x 8' for storage. But I can be convinced otherwise. I basically need floorplan for angled walls, etc. And materials suggestions (Tectum?). I am planning to use foam insulation for the inner walls. I'll post a floor plan very soon. My scanner is broken so I need to draw it with software. Any good shareware or freeware you guys can recommend? thanks all around! I could really use some advice. I have books but you people are invaluable resources. - Jim

So here is the diagram of the garage as is. I am hoping to build the initial inner studio/control room behind the tracks of the garage doors (though I certainly won't be using that space for cars!). So I would use the rear 23.5' x 19' (by 8' high) space to build a single sound efficient room for tracking and mixing. Please any help on materials and wall design would be appreciated! I will post a follow up with my uneducated initial wall plans and people can chew me up and spit me out (please: I have no pride I just want to do it right!). thanks, - Jim

Okay guys, here is my early uninformed floor plan. I tried to put any new walls or doors in BOLD. I am using the 19' x 23.5' (x 8' high) rear area of the structure. The new plans begin with a new wall just beyond the tracking for the garage doors; and then four new walls beyond that. I tried to (rather primitively) use Jeff Cooper's rule of 1' of skew for every 10' feet of wall length opposing another wall. I have no idea if I am using that rule correctly here in my drawing. I was going to insulate the new walls with Icynene foam insulation and maybe Tectum panels in place of drywall for the inner surfaces of the new walls. Also should I be thinking about slanting the ceiling above the mixing/control desk (which will likely be along the right (skewed) wall?? thanks! Please fire away with any ideas? materials? different wall angles? - Jim