As Emilio stated, more machine work required to get an 84 stroke VW journal crank to fit. As far as crank quality, the chinese cranks are OK, but you may have to go through a few of them to get a good one, and even then, they may need some work. Berg cranks are great, but they command a lot of money and sometimes have a long delivery time. DPR and DMS make some excellent cranks at a reasonable price. Before you go any further, have a chat with Kroc, GMB, or any other good engine builder. Anyone can buy a bunch of parts and throw them together, but what's more important is the sum of the parts and how they all work together. The difference being a smooth driving, powerful and efficient package versus something that makes all it's power in a 1500 rpm band and is hard to drive.
Your mileage may vary.