Tyler, I have been using a splitter that runs off my tractor hydraulics. It isn't the fastest in the world, being that my tractor is a beat up 1963 Super Dexta, but it seems to be at least as fast as a lot of the gas engine ones out there. It has the advantage of being less expensive (assuming you already have or are going to need a tractor with a Category One 3 pt hitch) than one with its own engine, and it is one less engine to maintain as well.
It has another advantage in that it goes from horizontal to vertical in a few seconds for those really big logs you will be splitting and can't lift to the bed.
Good luck with it!
Bill
Bill Grumbine
professional woodturner, instructor, purveyor of woodturning videos