Hope you had a great Christmas and New Year

I need some advice about roll cages. Even though I intend to compete in my miata again this year I am presently building another car (actually been doing this for a while now but am getting somewhere finally), and I need to clarify roll cage material specs, as well as pick your brains about classification outside of COM.
The car is to be a replica of the 1988 IMSA/ Trans Am winning Audi Type 44. Basically its an 87 Audi 5000 turbo quattro thats heavilly messed with. Although I am still trying to figure out if I am going to make it a wide body which would push me from SPA to PA.

Heres my first question...
1) Roll cage material - I have my cage mocked up in 1" conduit right now (pic below) and I went and met with my cage builder today to discuss getting the real tubing bent upI > need to figure out what material to use. In reviewing the SCCA rule book I ahve the following information.
Over 2500Lbs 1.5 x .120 DOM/Seamless/Alloy, 1.625x0.120 DOM/Seamless/Alloy or 1.75 x 0.95 DOM/Seamless/Alloy
The target weight for this thing is about 2700 lbs without fuel or driver, amd I intend to use Chromoly Alloy for the cage. Right now I am thinking 1.75x.095, however the bend radii are larger so I may need to drop to 1.5 x .120. Any recommendations?
next question...
2. SCCA and other clssifications - As I am building this thing, I want to ensure it can be used in other competition. Anyone got any Idea what SCCA / other classes of racing this thing might be eligable for? and how I find out? - here's the basics of the car specs.
1988 Audi 5000 Turbo Quattro. Totally gutted (SPA) wiht 8 pt cage (2 seats so no petty bar)
Suspension - Coilovers and adjustable bilestiens or Konis (bilies for now). custom front lower control arms, camber / castor adjustment plates.
Brakes - Porsche 996TT (big Red) calipers up front on floaring hat S8 330mm rotors. Rear brakes 1991 200Q vented disks and calipers. Converted to Tilton dual maste cyl and vacuum from original hydraulic assist setup. note Power steering also converted to electric PS from original hydraulic.
Drivetrain - stock AWD rear and 016 gearbox, front diff replaced with LSD, mid and rear diffs are pnuematic clokable. Aluminum Flywheel with custom stage IV clutch.
Motor - Initially - built 5 cyl, with ported and matched head and sport cam. custom inlet and exhaust manifolds. big hybrid turbo and intercooler with SEM fuel injection system (034EFI). Motor should be making approx 300+WHP. Later (if I like the car on teh track) I will switch to a fully built out 7A 20V motor which should make upwards of 500WHP, or maybe a twin turbo audi V8..but thats much later.
Thats it. I plan to get this thing on the track later this year, certainly wont be ready before the first event, but maybe by August.
Thanks
Timmy (Haydn)