I have a stainless storm lake barrel in my G19 that ate everything that went through it. It's up for grabs if you would like to purchase. PM for details.
I had a KKM in my g17 and loved it. I have a KKM for my 19 that I've only put a few hundred rounds though and swapped back to the stock bbl just because. Why are you wanting to swap it? Do you need a threaded bbl?