[South Texas]

I purchased the Coleman kt196 ($700 new at Wally World) for my son it's going to be his Christmas present and I am wanting to fix it up a little bit before he gets it. There is a website where I found some performance parts and I'm not sure if it will work on the buggie. I also would like to replace the wheels and tires on it(the aluminum wheels in the photo). My questions are since the buggie has a splined live axle where can I find some hub adapters to make the wheels in the photo work? I would like 18” tires in the back 16” in the front. I would want some narrower tires for the front could anyone point me in the right direction for the sizes available? Also will the performance kit in the photo work with the engine that is on the buggie? From what I have read it seems to be a gx200 clone. Is that correct? The photos of the buggie are from google as it is not assembled in a box sitting in the shed. Any help is greatly appreciated.