Hi Brett,
If I may...I feel that putting a one shot colour or a dslr on this beautiful scope mounted on Mach1 would not allow for taking a full advantage of this setup.
Since you are after wide field and you already have 8300 camera, then a natural choice is a larger chip - either KAI11000 or KAF16003. Both would also perform better than your SBIG on your larger telescope due to having larger pixels.
Having said that, maybe wait a bit before getting a new camera, and see what results you will be achieving with your current cameras - let your experience guide you
