I've got the 1750 rpm Woodcraft grinder that has now been replaced in their line-up with the comparable Rikon. In the case of mine, the factory wheels were no well balanced, so I bought the Oneway balancing kit. Then I bought the Oneway grinding wheels. By the time I bought all the stuff to make my grinder decent, I had spent enough money to buy a CBN wheel or two. And now that I've used a grinder with a CBN wheel, I know that's what I should have done in the first place. (Actually, CBN wheels weren't as affordable back when I souped up my cheap grinder.) The Oneway wheels and balancing kit are nice, but they don't hold a candle to a CBN wheel. I'll be buying one once I get my shop up and running.
My advice would be to buy the Rikon or find a good used grinder, use whatever wheels are on it for the time being, and then save up your lunch money to put a CBN wheel on it. (One is all you need.)