The newer fastcuts are the best, but probably the dearest, some of the older ones, like east / west mounted engines are the least desireable , for a number of reasons, the diffs are fairly straight forward and give you a better turning circle, and the best bit of advise would be to get the best condition one you can.....over model choice, they are easy to work on ,and most parts are still avaiable, they can be expensive and a machine that's been flogged will cost a truck load to put right.
Keep in mind , most tractor models that you will see for sale will at best need work and most likely be flogged out.
