Here is a site you might if you haven't been there yet:
http://www.zvis.com/dep/dep.shtml
As far as carbide dies, it may be just a demand thing and not worth the production investment to the major outfits. The case design in suitable for them though.
I also checked CH/4D and they don't have carbides either but I believe they will TiN coat a sizer die for you for a moderate fee.
Regards