Thanks Leon!
My son's answer is to buy another Ariens 27" walk behind and mount two of them in the bucket with a "funnel" directing snow into the two machines. The Ariens is 13 hp so the 26 hp makes sense. I already own the 66" rear blower and I want to use it since it's in good shape and very basic with easy to find and maintain parts and it works very well. The 4 stroke V twin would be easier to deal with than the hyd version...I need to give that more thought for sure. Chain drive would be easy to rig up and an electric start twin would make life easier too. The one self-contained unit would be easy on/ easy off and maint. would be simple too with all the parts from the local Co-op.
Think...think...think!! Has anyone out there done this type of conversion? Pictures?
		
		
	 
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The only real world conversion other than a loader mounted self contained 2 stage industrial snow blower I can offer you is a single stage snow thrower from finland that uses an air cooled 13 horse briggs with a chain drive for the high speed single stage rotor. 
Also In saying that Mott used a 4 cylinder Wisconsin for a three point hitch Interstater using a a V belt drive to the gearbox
and several folks in Pa. build horse drawn engine powered sickle mowers and I know of a builder of a towed motorized flail shredder that advertises them for sale in the Lancaster farmer weekly rag.
Its simple enough to do you just need the right gearing and V belt pulley size to run a 2 equal sprocket chain drive to run the snow caster.
The steel plate would or could be used to support the engine and upper sprocket mount on a bearing bolted to the steel plate and using a snubber sprocket to keep tension on the chain and use a belt drive with a larger driven pulley to a smaller pulley connected to the upper sprocket that would then rotate the lower sprocket to spin the gearbox as the primary drive method to the chain drive which would save on broken chains too. 
 
Timing cog pulleys and belts could be used bit I am not up to date on their pricing. They would be affected by wet weather unless they were shrouded and would require more work as the motor would have to be directly over the gearbox and would require enough room to remove the plates that hold the cog belt in place. 
They use cog belts for high speed rotary lobe blowers to drive them and they have used this method for many years.
All you need is time and multiple  pizza and beer bribes for a friend who may have a machinist as a friend if you do not own lathe or milling machine.   
The problem with the existing 2 stage ATV/UTV/RTV motorized snow caster design is two fold; where they should be using a closed auger design with narrower flighting to reduce the load on the impellers as  very little snow is actually powder snow and the open augers are counter productive with low power machines as the augers flights push the snow away where they should be carrying it into the impeller.
The earlier 2 stage toro units had this down to a science where the cross auger housing had two auger halves that had a solid tube upon which auger flighting was welded too the tube and the the snow had nowhere to go but in the impeller housing and out of the chute. Why they eliminated cross auger design as standard equipment I will never understand. 
If you added one of clarences impeller kits( he makes them for the (large rear and front mounts now)  to your rear mount you will have a snow blower that will not clog and operate almost as well as the new walk behind track drive Yamaha snow blowers.