I see a lot of people use .104-.105 fb with 105 Berger Hybrids.
Either reamer will work just fine. I would not recommend anything other than the two you listed so that you can run Alpha, Norma, and Peterson brass just fine. I believe the neck is a tad too much on the Manson reamer but it was done intentional due to carbon rings and bullet alignment.
I had JGS build my own custom reamer, which has .274 neck, .4705 web, .140 fb, and 1.5° lead to run Alpha brass and 105 Nosler RDF bullets. Works great.