Evan,You likely won't need the hi flow.If I were you,I'd build it,and if you decide later you want to make it a fully self contained unit,you can cut the beam off the SS mounting plate,add an axle,honda knock off engine,and pump/tank,and free it from the machine.I built mine for a specific purpose of splitting large rounds that couldn't be handled by one person or with out a machine ,into sizes that would fit in my OWB.Most times, I'm able to split over the dump trailer,and the pieces drop right in,saving another step. I wouldn't use mine to split normal sized wood,like was mentioned it simply costs too much per hour to operate,service,and maintain a skid steer to make it worth it.
I'll tell you one other thing I learned, overbuild the beam BIG time. I used a 6x8", 28lbs per foot,and reinforced it heavily.The beam shown in the pic,my cyl would bend that thing like a pretzel first big knot it hit.I still tweaked it splitting a 48" round of oak,I had to use the porta power,and heat to get it back,then add even more bracing.My Cat SS puts out 3400PSI,coupled with a 5" cylinder,it will literally sheer most trees of you want too. My brother owns a custom cycle shop,andh as a flowjet and CNC machinery,so he cut out all the cylinder mounts,and beam plates for me.If you want any pics of what I did,pm me.
If you build it as well as you port a 359,it should split wood like crazy!:greenchainsaw: