"My problem now is I have never ran a soup bowl piston. I love flat tops for max power and second best is inverted dome/D-shaped for lower compression."

I haven't either and I don't intend to at this late stage of my life. Same as you, flat-tops and D-dishes work well, why change?

"Maybe a thicker gasket to reduce CR would be better in this application???"

Wrong approach. CR should be set with the combustion chamber volume and the piston crown configuration. Then a gasket of the proper thickness should be chosen to work with the deck height of the motor to set the quench figure at 0.035" to 0.040".