Hi James,
I'm just trying to figure out what you're asking.
When you say will you get it up to setting 5 do you mean will you be able to fully utilise the pump on the fan controller, if so then I would say yes as the fan controller will allow you to put the full 12v/1.5 Amps through the motor.
Second bit about the 655 PWM might cause you more of a headache though.
The information I can find about the 655 pumps is that the 655B is stated as being 24 Watts which the fan controller "should" be able to cope with, the PWM specs are up at 37 Watts which is outside the stated operating range of the fan controller.
I'm using a pair of 18 Watt DDC's on mine without any issue which is why I can say that 18 Watt pumps will be fine, B NEGATIVE stated that D5's run without problem at 24 Watts on the V5 controller. I think that the 37 Watts of the PWM might be a push too far, but without extensive testing I couldn't say for sure. I would advise sticking the right side of 30 Watts on the V5 fan controller though. I think Lamptron do higher power fan controllers but I believe these are switched rather than variable.