This is what makes this forum great! Plenty of good advice for everyone. I got my, now 10 year old, son into this hobby 15 months ago with a HPI RTR. Found a local race track and spent a small fortune trying to hop up the Sprint 2 into a racing TC. Glad you did not start that way because the Sprint 2 is now retired into a drifter/basher. Might be good enough in 17.5T class but my son progressed into 13.5T and recently 10.5T stock after a TQ/A1 finish. The RTR just couldn't keep up. We went thru a Spec-R, a TCXX and a couple of S411s the last 12 months and he is now on a Top Sabre S4 due to a sponsorship. I had the experience of building the sakura Xi sport due to an upcoming one-make endurance race where everyone's got to use this chassis. Got to say it was a delightful built and I have no reservations that you could grow with this car. Design, layout is top class and quality is right up there at 1/4 price of a big name chassis.
My advice to you is get a thicker bodyshell as the lightweight ones cannot take all the newbie beating
and to read up all the Lipo battery charging/storage instructions as well as proper gearing for your motor. I blew up a few motors, ESCs and damaged a few lipos at the beginning because I didn't know what I was doing for my son. Also, ESCs cannot take reverse polarity so best for you to use Deans connectors. Its possible to plug in bullet-type leads incorrectly when you are in a hurry or when you are simply thinking about something else
The other advice is to keep reading this forum as there are plenty of useful threads! Good luck and have fun!