That's usually what I do, I prefer to build my own but usually with stock parts and then upgrade when needed.
Most important thing is to have fun with them. Always a plus when the kids are involved.
Welcome in @Teefy , a couple things you need to watch out for.
Changing to a bigger wheel and tire could put stress on other components.
Chances are the motor and esc will heat up pretty quick.
If it's a brushed motor then it will most definitely heat up.
We are kind of limited by our...