I have an IO-375, but I am not flying yet. When I was researching engines and props, I came to the conclusion that none of the Sensnich fixed props would work.
I think you could have a prop maker (Catto, etc) make you a fixed prop that would work with an IO-375.
For what its worth, I decided to use the Hartzell BA prop that Vans sells for the 180 - 200Hp IO-360s.
Hope this helps,
RV-7A (Flying and Sold)
RV-10 in process (@#$$%# Cabin Top & Doors)