The wheels and tires look to be ones from a Chinese scooter. It is a little hard to tell by the pictures due to the perspective, but I'd guess both front and rear are 10" wheels. This is just a Kentucky windage guess on the tire sizes. The front tire I'd guess to be a 10x2" or a 10x2.5". The rear looks wider and taller my guess would be a 10x3", 10x3.50", or 10x4", but I couldn't find any on eBay wider than 3" in that style. You'll want to check your axel diameter and bearing ID to make sure those wheels would fit or what modifications would need to be made to make them fit. Though I believe motovox already uses metric axles and bearings in their wheels. Still best to check to be sure.
If you're running a 212, a stage 2 "race" setup from GoPowerSports with a 24mm Mikuni flat slide should be plenty of power. Plan on spending over $500 for everything if you currently have a stock 212. That includes the stage 2 kit, header and bigger carb. At that point you'll also want to upgrade the brake if you still have the stock cable operated one. Adding the front suspension with the front brake setup is a nice, albeit pricey, upgrade too.