My two cents:
Ed Brown is a good parts maker. I like their thumb safeties especially. Their parts are also reasonably priced.
I'm also a BIG fan of Cylinder & Slide.
If you're going to spend the money on parts, try and make sure they aren't made by the MIM process. Many of the inexpensive ones are. Oh they do work, but for how long is a huge topic of debate. No point in going there really....but if you're gonna go through the trouble to improve your pistol......nuff said.
Also do yourself a favor and go slow and ONLY change something if you have a good reason to change it. There's no point in changing something for no reason. In my case, all my guns are made up of various manufacture's parts, but I don't do this for the heck of it either.
Since you're planning on beavertail work........
I'm not an expert on the Norinco frame, but most likely you'll have to fit that beavertail to it.
There are somewhere about 30 varieties of grip safeties out there right now. Some are "drop in" and the others will either fall into the "Ed Brown" or "Wilson" genres.
What you want to know, AHEAD of time, is the radius you'll have cut on your frame. There is the .250 radius, which includes Brown, Baer, and McCormick etc, and there is the other which includes a Wilson, Caspian, and others.
Whatever else you do....ORDER THE JIG before you go grinding on your frame. Most jigs will come with instructions.
The other thing is fitting the safety "hand" to the trigger bow. This is a real sensitive undertaking. One extra stroke of the file or even a stone, and you've got scrap metal for a grip safety. Aftermarket grip safeties come oversized on the hand for that reason.
My suggestion on that is to fit it carefully by only installing the trigger, mag release, mainspring housing, and the thumb safety pin through the right side. This way, with a good flashlight, you can observe the working of the grip safety against the trigger bow as you proceed to fit it. Follow that 45 degree angle on the hand also. Don't change it, or you'll regret it.
Another thing you may run into is having to file off some of the top of the mainspring housing to get the proper travel for your grip safety. A grip safety, in my opinion, should NOT release unless you have a proper and firm grip. I run across grip safeties that release if you just sneeze on them, and this, again in my opinion, presents a safety hazard during carry.
If you DO screw up the hand, there are other options that can get you out of trouble, but there's no need to talk about those right now. *smiles*
Oh yeah, and "Dremel" tools are all demon possessed! Avoid them at all costs.
Good luck....and let us know if we can help you.