I think the biggest drawback with an 8 mm is bullet selection, or lack there of. You will be very limited on your bullet selection.
Another problem would be cost. This is a wildcat.....no factory dies. Custom dies are not cheap!!! Best case would be a bushing die with proper bushings. I did some costom loading for a 7mm-300 wby and simply used my 300 wby neck die with the proper bushings. I don't know that this would work with what you want. As far as FL sizing a wildcat with a standard die......I think you would be out of luck.
I agree with the other guys....7 stw, 30 378, 33 378, or a Lapua.
But, if ya gotta do it....let us know how it works out!!!
Good luck, and have fun!!