There is little doubt in my mine that the intake port on the Stealth is the edelbrock design. Vitually identical. The exh is slightly different, because they are not raised, they are more of an Indy SREZ design. A cylinder head casting core contains several inner cores. The intake port, the exh port, and the cooling passages, plus the external shape. So you can copy each one, and then place them into your own external design. China and 440 source copy. Plain and simple. But they combine things in a nice way IMO. The execution is marginal, but so is everyone elses.
In terms of bring in Jeff at Modern (who i have talked to personally and used product from) as "just some guy" is really, really shortsighted. He is simply one of the best head guys in the US right now for domestic type V8s. The CNC program he has is not, as I understand it, the Edelbrock ones. BTW, there are a bunch of programs for each type of head. It's not one program for them all. RPMs alone have at least 4 as i know it. A cnc port design starts with hand porting and flow testing one port of each hand (there are rights and lefts) on the intake and exh, then digitizing the resulting design. You can't simply apply one program to a second manufacturer.
The heads flow similar after porting. IMO, the only thing I would use from 440Source would be the valves and castings. I won't trust the rest of the heardware, or the machining. However, most RPMs I use get the same treatment. I think the RPMs are a better product, but yes, I'm a walmart boycotting "made in USA" type shopper too. I cant eliminate all the exporting of wealth, but I can help lower it a little on identical product. Stealths are not identical to any single product.
Buy what will work for you, fits your budget, and fits your moral fiber. But understand there will be work required by all of them.