I just purchased a Kubota M7060HD12 ROPS. I ordered it with an extra set of hydraulic valves, front end loader, cast wheel weights with the wider tires and liquid ballast. The total out the door was $39K. I hoping this will be enough tractor for me to use a 84" rotary cutter in some fairly thick brush/sapplings. I looked at going with a smaller tractor but when looking at prices, it only made sense for me to go bigger.
Your 7060 should be sufficient for a medium duty 7' cutter in most conditions so long as you do not get carried away with speed. Trees are another matter.
A bit of advise.
If your cutter has front chains, replace them with rubber belting once the heavy clearing is done. Belting is much more effective in keeping debris off of the back of the tractor and operator than are chains.
Make sure that the mower slip clutch is adjusted for the PTO HP of your tractor and is not frozen (common). If it is frozen or adjusted too tightly, you have little or no protection for the internal components of your tractor.
It is easy to puncture tires when cutting saplings. If you do, you will loose your liquid ballast and create a mess. Dull blades are best for saplings because they tend to not cut the saplings off clean.
Unlike, most, I keep the blades on all of my rotary cutters sharp but do keep a spare set of dull blades for saplings.
SDT