Jebao RW-15

I'm thinking about investing in new pumps. I have sun sun and koralia right now lol. I have a mixed reef in my 40B with clam, goni, various sps, but it'll be half and half eventually. I was thinking 2 Rw-15 but it might be too strong so 2 Rw-8's? I also bought an MP10 but going to sell it since I heard it isn't enough? Unless it would be so let me know