Looking at your pics again I see the potential to reduce the tractor RPM and still get 540rpm to the blower, by using different sprocket sizes on your driveline and the blower input shaft. Then you could run the tractor at, say 2000rpm to achieve the 540 at the blower, instead of 2500rpm (if that is what your tractor calls for to get 540 PTO speed). That would likely reduce the fuel consumption and make it a little less noisy in the cab. Or you could run the blower at higher rpm's to get more volume through it and throw the snow further.
When I converted my rear facing blower to front mount, with a homemade rear hydraulic power pack, I did a similar thing using a chain drive and sprockets of different sizes, to achieve 600 rpm at the blower input shaft. I ran my old Meteor snow blower on it and consulted with the manufacturer to see if they thought the higher rpm would be a problem and they said no. It certainly thew the snow further but lacked the torque I was after, even at lower rpm's. In the end I gave up on the project because I couldn't get a high enough pressure motor to produce the torque I wanted. I then went to the rear inverted blower and so far I'm happy with that choice. But I only have 1/2 a season running this setup. So more time will tell if I have the best (or as close as possible) setup for my needs and conditions. Hope yours works for all your needs and I can't wait to see it in action.