Piston advice needed

I am building a 545. Diamond flat tops (40512), top ring is .285 down, 14-1 compression. 6.7 rod. P51 heads. After square decking, I have 12 thousandths positive deck height. I can use a .056 Cometic and have .044 quench, or I can take the pistons somewhere and have them cut down. What are your thoughts? What are the disadvantages of running a positive deck height?

Thicker head gaskets will work just fine