I would like to get about 8 GPM to run the log loader/grapple as anything less pulls it down a lot. After looking at the HydraBuddy it doesn't seem like it will produce enough GPM and overall not sure of the quality. The one advantage is I could pick it up at northern tool and eliminate shipping. Any other manufacturers that one might suggest to look at? At this point if I can get one for under $2,000 I believe it is best to buy rather than build.
You might think about this a little more. Do you want log splitter ability, like 11 GPM at 650 pis, and 3 GPM at 2500 psi all the time. It could work, the log splitter would work just fine. and if you hooked it up to a grapple, the 11 GPM might be a little fast. You can control that with a valve, or run the engine slower. Only needs 5 HP.
If you want 3000 psi, and about 8 GPM maximum, the engine requirements are a little different. To pump 8 GPM, at 3000 psi, you would have to have a 16 HP engine, but you would have the 3000 psi for the power.
And all the other stuff like hoses. QD, valve, reservoir, maybe wheels.
Some time ago, Sears had a combination log splitter, and it a hyd pkg that did what you want. Had the hose, QD's, valves, etc.
If you already have some of the stuff you will be ahead. If you build it as a log splitter, you might be disappointed with it doing other things, where as, the 16 HP , pumping 8 GPM at 3000 psi will do it all.
Just some stuff to think about.