No doubt someone will jump in to prove me wrong on this, but I have figured if you are buying new equipment and not putting it in commercial use, the price of most replacement parts from one brand to another probably doesn't mean very much to the total cost of ownership over the years. Sure, one brand's alternator may set you back more or less than another's, but maybe you only do it once in 20 years and there's a pretty good chance you will never need to replace it.
If you were being nickel and dimed to death with constant repairs (I've sure had some cars like that!), it would be a different story. That could happen with older equipment, but does not seem to be the pattern with these smaller tractors. As long as you aren't pushing them beyond their intended capabilities and take good care of them, they should last a long time for you with reasonable maintenance expense.
That's not to say you couldn't get soaked by some greedy dealer on repairs, though. So, unless you plan to do your own work, it's important to find someone who's been around for a while and has a good reputation.
Good luck making your plans!