Belts used are T2.5 with matching pulleys on the motors. You can use any belt, as long as it fits through the holes on the drive wheels back to back. Best if it is a tight fit, because I don’t have to use any other mounting but friction on my two prototype machines.
I used chipboard screws to attach the Z mounting brackts, but this depends on the platform material. You could even glue it down with silicon… Be creative!