I bought a Rhino 900 with a 6' blade that would tilt swing and angle. I bought it to cover trenches that I had cut for buried underground cables. It worked extremely well. The only problem was that the tractor (TN70D) was to big to easily maneuver in the tight areas that I had to work. I wound up replacing it with a 6' 6way dozer blade for the front of my skid steer. For the work you are describing I think the 900 would work well for you. It was very well made and I could control all the functions from the cab of my tractor. Seems like I gave about $2200 new for it including the rear remote splitter valve.
Tim
Tim