What speed is the snowblower designed for? If you run a 540 snowblower a little faster (I would not recommend full out 1000 rpm) it will probably perform very well. But you will have to run your tractor at less then rated RPM speed and the question is, can it deliver the required HP at that RPM?
Many forign (sp?) compact tractors had multiple RMP PTOs, something I was most jealous of on my unimaginitive Domestic tractors. Only larger domestic tractors seemed to have 1000 rpm PTOs. So, it might have been a nice option to run low demand PTO implements without the engine screeming away at full RPM. However, most snow blowing operations demand much of the tractor. Our JD dealer once told me that blowing snow is the hardest thing many tractors will ever be asked to do.
It also depends on your drive system. A hydrostat or multiple speed transmission in the direction you are going can make better use of available power. If you only have two reverse speeds like I do on our JD 6200, one is too fast and the other is too slow! Fortunately, I have a wet clutch, but it's still all no good!