For Inferno GT2, usually original motor is good enough. However if you want more performance, you can try Picco .28 p3, OS .28 ZX or maybe .21 engine too. Keep in mind of the stock clutch, you might want to replace to 3 shoes clutch and flywheel. (I have new one for sale if you are interested). Because the stock clutch spring is very easy to break.
For tires, you can hardly find foam tires out there. But you can try buying rubber tires in KWS. They have much better grip than the stock tires.