There's plenty of suppliers out there to choose from. I'm sure you could find a crankshaft for your 196 on Amazon. I recently threw some parts into an engine. The parts I used came from NR racing, Studz racing, and eBay.
If you order engine parts there's no need to be specific with "Hisun". Your engine is a Honda GX200 clone. Most every major supplier should have clone parts. Here's an example:
DJ-1275 Clone 196cc/GX200 Stock Crankshaft - ARC Racing
Over the years a lot of guys have bought new engines as a solution to the 16mm crankshaft. It is a good option if you have the money because you'll be starting with a bigger engine 208cc or better. And these days there are a lot more engine options out there to choose from and just about every one of them are a better option than a Predator 212. Early this year I was close to getting a 208 from Northern tool for $135 shipped but ended up choosing a 224.
The only thing "wrong" with the Hisun 196 is the crankshaft. They are a better quality engine than most know. I recently did a bare block side by side compare of a 224 block versus a Hisun 196 looking at the inside of the block. The Hisun block casting and a few other details were much more impressive than the 224 block.