We've some work on a three point hitch here: https://wiki.replimat.org/wiki/Three_point_hitches
Hydraulic motors with PTO splined shafts are widely available like this: https://www.surpluscenter.com/Hydraulics/Hydraulic-Motors/Ag...
Hydraulic motors with PTO splined shafts are widely available like this: https://www.surpluscenter.com/Hydraulics/Hydraulic-Motors/Ag...
Please contribute anything you know about custom hydraulic lines to https://wiki.replimat.org/wiki/Main_Page - I will approve accounts for any hackernews folk who request one.
I appreciate all your points about the sort of tractor best suited to your unique circumstances. I don't see anything about our communities designs which prevent you from constructing such a machine using our parts and techniques. I think it'd be a neat design to have among all the others which can be built this way!