Not sure what you mean with this one my freind.
You say you want to get in to MotoGP racing, but then say you will never be on the pro circuit.
As for only riding upto 150 will not help you ride in MotoGP.
The MotoGP ( Dorna effort ) travel the whole planet from the Indy 500 track to Europe to Japan. Everywhere.
I dont know how many road racing tracks there can be within a 150 mile radius, but it cant be that many.
In the US, all the pro racing is under the AMA, so you could try there website for " start racing " links, or try RoadracerX website. They are very usfull in this line of work.