If it were me I would still hold out for the single stage Riest pull behind ONLY because you will have all the torque you can use since all the torque delivered is being sent to the chain drive for the snow blower rotor. They can add wings to the unit they have and the single stage unit has much more steel in its construction. The lower cost would let you go up one or two engine frame sizes too.
For the money that they want for it you could have them add chute spot lights and rear marker lights too.
The lower cost of the Riest single stage will let you go up one or two engine frame sizes for a purchase and the power take off would never be short of torque to spin the snow blower rotor as it has four paddles in the center for direct discharge up the chute.
With heavy wet snow you going to have to go a bit slower anyway but with the single stage unit and a larger mule/engine frame size you will never lack for torque under any condition.
You can always add slick sheet material or paint the interior of the snow thrower and the cross auger with slick plate paint to prevent snow hanging up and the single stage will not clog like a 2 stage will either as the construction of the machine is fully open and exposed except for the rear portion of the snow blower rotor housing which has an adjustable gap to allow the user to throw even more snow rather than have that 1/-3/8+ inch layer amount of snow staying in the housing for each rotation of the snow blower rotor.
As I have mentioned before I never had a bit of trouble with the 12 horse IHC Cub Cadet with the horizontal Kohler engine I had with the single stage snow thrower that was belt driven through a right angle bevel gear box to the cross shaft that spun 40 roller chain to power the snow blower rotor. I had to take smaller bites in wet slush but other than that it was never short on power.