What reactors are you running ?
If you don't ever need to adjust your reactor flow rates, nevermind
I know you're looking for 15-1800gph, but ...
An Eheim 1262 would nicely replace your Mag 9.5 just as a return pump.
I run mine internal on a 1" pad and it's virtually silent.
I tried running multiple assessories on one pump and had level adjustment issues.
I ran one pump for my UV, Chiller, 'Fuge and 2 x TLF 150s. Everytime I had to adjust the flow to one of my reactors, it would mess up my fuge level.