I am running the outer axle seals that you are attempting to run, and I see how that shoulder would pose a problem. I don't think you are going to find a seal to work with that shoulder.
Rugged Ridge/Alloy USA simply are not going to have a solution for you. They only offer two inner diameter options, and neither one of those is going to work with that tapered shoulder.
There are pros and cons to those outer axle seals. I know my local axle shop really doesn't like them. Their most important argument is that water can get inside the tubes (particularly if turning during a water crossing) and then not get back out. Water crossings are not part of my world, but desert dust sure is. Those seals serve me well, so I continue to run them.