Whatever floats your boat. I wouldn't do a 285/35/19, though. I like the wheels/tires in the back to be taller than the front. It isn't much of a difference when using math...but when looking at certain brands...they can differ by 1/4 inch or more.
In that regard, I would just do a 275/40/19 in the rear.
2013 Mustang GT - 402A GT/CS - 6R80 - Glass Roof - Engine Block Heater - SGM Exterior - CB/Miko Interior
Steeda Adjustable PHB (Street) and Steeda PH Brace, Stainless Works Retro Catback Exhaust...