Welcome to the forum David
Glad to see you are getting into photography and learning new skills. To be honest with you I wouldn't bother buying a new 18-55mm. Instead I would buy the camera body only and put the money saved towards another zoom lens, maybe the 15-85mm could be considered in the future (or one of the Tamron alternatives).
The 70-200mm f4 is a great lens and you can't really go wrong for the money. You should consider if you will need IS though. For Motorsport you won't since you will be using fast shutter speeds, but in other everyday situations you might not. I haven't read much about the 150-500mm so can't comment on that although its a very different focal range which should be considered.