Pitchka, we all want to know, where on the TC website this is mentioned. Really. Because in general, 500h is one of the numbers where the first time complacency comes up. At 500h you are less safe than at 200h. At least that's what I learned during my FI-course. I am pretty sure you got something wrong there. And I am also sure, there is no certification or anything. We only jump on terms like that, because there are so many terms that are used by laymen/the press/I-know-everything-guys that are used wrong, out of context or are misunderstood, that we just can help ourselves to get giddy.
Oh, and BTW, the H125 is the better option. Speed is not the deciding factor, climb rate is. Sitting in a 407 with ski boots is way less comfortable than in a H125 and getting in and out on one side only, too. And don't go for the leather seats.
And one more thing. A single ship operation is completely useless in heli skiing. The helicopter has to be there when conditions are right. If it is down for maintenance and you don't have another ship, nobody is going to book you again. And this will happen. Helicopters are not cars. You can't just wait another 20 or 30 hours for scheduled maintenance. And if some clumsy customer does some damage, your helicopter might be grounded for quite a while.