There are two sizes for the Rollz Motion - small and regular. (The Rollz Performance only comes in regular). The width of the regular and the small is the same. The handles are adjustable for height so, unless you are really short or really tall, you can have either the small or regular. The big difference between the two is the seat height - 50cm on the small and 55cm on the regular. The small only comes in Island Blue and Matt Black. The Rollz Motion will take someone up to 125kg though at the upper end you will need to check if the seat width of 45cm is ok. There is no bariatric version.