Hi Again
The 9" Compos on Bay are ET-12.....That's a NO NO based on the dimensions you provided
These wheels will be approx 10" overall and will extend out from the mounting face 5.5" Beware. If you have metric studs you can get conversion wheelnuts to suit Grp4 wheels direct from Compomotive
In relation to the 8" wheels at ET0 they will have 4.5" of wheel outboard.....Hope that helps