What is the difference between the HPI Sprint 2 Sport and the HPI Sprint 2 Drift Sport? what are the top speeds on these cars?

I have been looking at these 2 cars for my son (9yrs old) that Id like to get him. He has an HPI RS4-3 18SS with the Stage-D kit (you can see pics in my file) and many hop-up parts. I hate the fact that the car has to be pullstarted, warmed up then for it to shut off. He cant pullstart his own car so I rather get him an electric on road HPI rc to all he has to do is just charge the battery pack.

And wich should I get for him? (Keep in mind I can still use the hpi aluminum shocks and the hpi stage-d drift chip)

I was also thinking of getting him the HPi Sprint 2 Flux... but what is the top speed on that car?

Thanx