Changing to bigger wheels, need help.

[Hoosier Vette]

I have on the front 17x8.5, on the rear 18x9.5. I am looking to change to possible 19+20" wheels. Should I stay with these size wheel widths or go wider. I dont want the tires to stick out past the wheel well. And I might lower the car. If I go with 19+20" can the tire sensors still work. What suggestions do you guys have for tires.

[printmanjackson]

add 1" to both and they won't stick out