There are many types used....Some brush pulls use a simple back blade on a tractor (works fair on a hard track, awful on a soft track). Some use a bobcat and simply back drag.
The "preferred" unit is three point mounted From above it would look something like this:
You may find that you can buy one for the cost of the materials. The ones from Agritec as listed above are very nice with high quality paint and welding. As a side note many sled operators will rent you one for next to nothing.
Those are the ones I have seen used for decades. Work great as long as the man on the tractor knows how to operate it and doesn't start leaving waves on the track.