Be careful when shaving those domes. I have some TRW/Speed Pro forged domed pistons and the domes are hollow on mine. The company was bought out by Federal Mogul and we realy got screwed in the process. They used to have a great web site with tons of useful information but that was taken down at some point. I had saved a copy of the info from the site that might be useful here. "Some domed pistons can be modified to a flat top, to lower compression ratio, but this is not a job for the home engine builder. A minimum head thickness of .180" for forgings, or .220" for hypereutectics must be maintained, with greater thickness required for endurance, nitrous, or blower use." Watch the underside of the piston and take careful measurements when you decide to have them milled.
I thought they also shut down the forging factory too. None of this is a good thing for our hobby.
I hope this is helpful.