360 compression issues. pick a piston??

I have some issues. I have a set of speedmaster 65cc heads, and a 360 i intend to build. My machinest and i agreed to go with 9.8-1 compression to run it it on pump gas. He is recommending dished pistons, and a .040" MLS headgasket to keep the compression where it needs to be.

I also talked with a mopar buddy who said just use flattops with 5cc valve reliefs in them, and a .100" MLS because of the loss of quench with dished pistons. Then if i want to bump up compression later on, i can just drop on a thinner headgasket.

While both ideas have merit, i want to go with the most bang 4 the buck, and get some decent dyno numbers on this when its done.

Any thoughts on this
Thanks
Matt