IDK which country you are in, but Id say avoid Amazon. Get it at a brick and mortar electronic store near you that has a good warranty and return policy.

The switch itself comes with wireless joycons that allow multiplayer out of the box. Assuming its mostly for the kids, it should be just fine if you got mariokart and the wheel attachmemt for the joycons.

A nintendo pro controller is a steep $70 and third party ones are hit or miss, espeically if you are a casual and dont wanna mess around with connection problems. Just getting more joycons is a better idea since its got funky colors and can do a bunch of motion control games that you cant with the pro controller.