Descended from the Arminius revolvers of the 80s and, like them, largely made of- (you guessed it) potmetal.
The finish is electroless nickel over a zamak barrel shroud and (on .357 guns) carbon steel frame. They don't make an actual stainless model.
Not sure about grip options, someone might make something- you can check EAA's website to see if they offer any as accessories.
I've handled, but admittedly not fired, a couple and was unimpressed. Across the interwebs, some folks think they are a great value and others have had timing and a accuracy issues.
One thing EAA is especially notorious for is poor CS if you do have a problem. Repair parts availability is pretty much nil as well.
For me, they are a hard no. I would put that $350 towards something better, even a (shudder) Taurus....