ralph372, I researched this same question hard back in November and the consensus was that although a skidsteer mounts in front (because they have no choice) the rear of the tractor is better suited for this as with a hydraulic down pressure auger you need lots of weight to keep it on the ground when drilling thru Limestone or solid rock. I ended up with a Beltec hyd auger equiped with a 2" puff drill for tpost and a 12" rock auger. It is a very expensive setup I have around $6,000 in the unit and augers but I can drill a 6' x 12" hole in solid rock in about 15 minutes. Its cool but you better have a lot of holes to do to warrant owning one. Renting around here was an option as well but it was $300+ for a weekend and I've got lots of holes so I bought it to save money and so I could do it at my own pace instead of the hurry up its almost Monday method. By the way if your set on having it mounted in front make sure you get the skidsteer quickattach universal front end, you won't find a hyd auger to mount on the front of a normal tractor loader frame, at least I didn't.
Steve