Up front, I dont have a 35 Whelen so cant compare. I do have a 9.3 that i had built (re barreled and cleaned up a little) on an Interarms X action for bears and elk and absolutely love it. I've shot and had good luck with 286g, 270g, and 250g bullets but have just stuck with the Speer 270 as they have worked well on everything they hit and are accurate in my rifle. When i had mine made, the 9.3 hadn't really caught on so was kind of an oddball (which is why i chose it over the 338-06 and Whelen) but now, it's got a solid following. Mule Deer has tons of experience with the 9.3 and has written/commented on numerous threads with great advice.
Like other have said, here in the US i seriously doubt you would notice any difference on game so it's a matter of picking the one that floats your boat. I would do a quick internet search and see which is easier to source right now...that may help you decide.
