50' elevation change over 75 acres isn't a lot, but what is the steepest individual grade that the tractor would have to climb, and would that be while working or just while traveling to do the work? Another question would be how muddy does it get when it rains. I know that a lot of Texas was going through quite drought recently, so you may need to ask your new neighbors how muddy it gets when it does rain.
If the steepest grade isn't too steep, and if it doesn't get too muddy on your land, then I would go with 2WD and more hp. If the tractor is going to have to do any hard work while going up a steep grade or while the ground is very muddy, then I would go with 4WD, which for the same money would mean less hp.
If the steepest grade isn't too steep, and if it doesn't get too muddy on your land, then I would go with 2WD and more hp. If the tractor is going to have to do any hard work while going up a steep grade or while the ground is very muddy, then I would go with 4WD, which for the same money would mean less hp.