Bad choice, I'm afraid.
You would have 17 GPM at 2800 RPM with that pump and that's too much flow for the size of the plumbing in these tractors.
If you want to extend the life of your pump, then install an oil filter capable of flowing 15 GPM minimum while filtering out contaminants down to 10 microns. Change the hydraulic oil once each year and the filter cartridge every second year unless you are exceeding 500 hours per season on the hour meter.
Danuser is one maker of hydraulic augers but there are others.
If you want to go out and dig post holes for fences and decks in back yards, then choose your hydraulic digger wisely.
Do you have frost issues in your area? Where I live, we bore a full 4 feet deep to get below the depth of frost. If you don't get below the frost line, then the frost will push up on the posts every winter.
What size holes do you intend to bore? I used to use a 10" auger for 4 x 4's and a 16" auger for 6 x 6 posts.
I prefer double fluted auger bits with individual teeth on both flutes that can be easily replaced along with replaceable starter tips in the middle of the auger.
With a hydraulic auger, you can go with HEX drive instead of round drive with a shear pin.
Drilling holes is a job that is tough on equipment. Even in virgin ground, you can expect to find large rocks, tree roots and sometimes boulders so large that the hole cannot be drilled. In subdivisions, you will encounter clay soils that are packed like concrete as well as every imaginable piece of junk known to man buried below the surface.
If you choose some lightweight unit, you will regret it. You need to have a spare auger for back-up along with spare teeth and tips. Do your homework first. Talk to people who make augers. Talk to people who drill holes for a living such as fencing contractors. Learn which brands and models stand up to the test of time. Learn how much these units cost new. Then you will know what is a good deal and what isn't. Your market is probably the DIY guys who want to build the fence but don't want to hand dig the holes. Now, my hole sizes may seem too large in your eyes but it's tough to drill perfectly straight holes that are also in perfect alignment between the two corner posts.
http://www.equipmentland.com/products/b ... ndex.shtml
http://www.wikco.com/dhydaug.html
http://equipment.forconstructionpros.co ... ttachments