You need a lot of oil to handle all the heat of such a high-power, continuous operation.
You don't want the oil tank on the blower - the blower is pretty heavy already, light rear end on the tractor. You would also need a lot more big suction hose - in cold weather, tank near pump = good.
Be aware of the power loss you get by converting mechanical into oil pressure & back to mechanical. Most CUT tractors have little to spare for running a blower, you will be losing at least 1/3.
You don't want to run anything else off the pto pump, not even a little cyl or orbit motor. That blower fan will need all the attention possible.
You are going to spend $400 for the pump, $400 for the motor, $100+ for hoses, $100 for the oil tank, $130 for the oil itself, or $1130 plus some odds & ends we aren't thinking of (filter set for all that oil?), to replace a $150 pto shaft. Plus you will lose 1/3 of your power.
Think this through carefully. There is a good reason you only see hyd blowers made for machines that have no other option but come with a big oil pump already.
--->Paul