There are 3 main sized karts available for bitumen racing. Within the 3 sizes they can than be narrowed down by frame & axle diametres. The frame shapes would be different too.
Typical nicknames for a kart size is cadet, junior & senior. A kart wheelbase length is mainly so the driver is comfortable. Karting Australia does specifly a kart used in junior or senior class to be over 1000mm wheelbase but drivers usually need that length at those ages.
Cadet is 900 or 950mm in wheelbase with 30mm axle & 28mm frame tube.
Junior is 1010mm wheelbase with 30 or 40mm axle & 28mm frame tube.
Senior is 1050mm wheelbase with 40 or 50mm axle & 30 or 32mm frame tube.
Click on the kart logo for which karts that brand offers for your class.