That's interesting about the splitter. My understanding was that you could get PTO driven ones. I liked this idea since I would assume it would be cheaper and simpler in design (no engine, just a pump, value, piston, etc.).A wood splitter that runs off the tractor hydraulics will be slower and less powerful than a standalone splitter. Tractor hydraulics do not have as much flow or pressure as a dedicated splitter. With careful shopping the cost difference is small, only a few hundred $$.
How large a chipper do you intent to run? And how large will the material be that you're chipping? I have a hydraulic feed 8" Woodmaxx and find that of all the tasks I do, chipping is the only one that makes me want more than the 37hp my tractor has.
A chipper with a large throat is useful even if you're chipping small stuff because you can do less trimming. Power feed is much safer than "self feeding" chippers, and hydraulic feed lets adjust the feed speed.
As for the chipper, I am shooting for something rated for 3", but I'll probably stay under that, anything over I'll just cut and stack, or burn.