Forged stroker pistons - recommendations?

I've used Ross, SRP, Diamond, and Icon. With the right bore clearance they are all quiet. They als all have short skirts to clear the crank counterweights and all over time and use will leave marks on the cylinder wall - especially the lower 3rd of the bore and on the major thrust side. That's where the skirts are during the hardest "push". I'd suggest you verify the bores are perfect (via measuring), have the block sonic tested to determine the strength of the walls, and then determine if new pistons can be used or not. That will depend on the existing bores and the recommended wal clearance of the different manufacturers. You may find there are no usable pistons for the wear without going bigger.
Yes, you've described exactly what's happening.

I'm expecting to go bigger bore. As mentioned, the pistons were originally clearanced for NOS, which I decided not to use (I'm already in the 11-second bracket and want to stay there).

The engine has a 180F thermostat and does get up to operating temp on the road, but takes a while to get there and a little time to warm up. But even when it's warm, it slaps (due to the extra clearance).

I basically want a more "street-friendly" piston. As far as I know, no-one makes flat-top hypers for Mopar strokers, so 4032 forged would be the next best material as far as I'm aware.

I have an early casting 360 block, so I should be able to go 4.04 easily - possibly 4.06 or 4.07 (currently +0.030). The block will be getting sonic tested first to make sure, but I also have access to another early 360 block if mine isn't suitable.

That said, I'm inclined to go for +.040" or +.060" flat-top piston. I could go dish, but I'd lose about 1 point of compression - from 11.4 to around 10.4 - so that's not an ideal option at this stage, especially with alloy heads and a decent roller cam.

Thanks for the suggestions so far - I'm happy to hear more!