The tractor GL shows is the current model which is the mid size. Hence they do come bigger and smaller. The smaller ones are not worth it as they just can not do the work required. One small bit of info though the first two numbers designate the Horse power.
Reng Ma in Thai.
47 in GL's photo. They used to be 34, apparently the 34 were more reliable then the current model 47. So the farmers say, at the front of the rice buyers all chatting.
Bottom line is that they are not cheap. And don't forget the plough and rotary tiler are all extra.