Many different ones you could get.
Manco is one builder that is good, they are out of business now but there are still karts and parts around that meet your needs.
Yerf dog is another brand that’s not quite on par with manco quality but they get by. The spider box is the model like a buggy with electric start and all that jazz.
I have both manco and yerf dog and prefer manco simply because the frame is braced better.
These are karts that are already made and you would/possibly need to fine parts such as tires,seat,etc...