Thanks for the tip. I will look into the Lavac. I don't know if they are available here in Australia. I have only had experience with the Jabsco thus far and as I have inferred it sometimes takes some encoragement to prime.
As this is a new boat I am concerned with the invasiveness of the procedure as the local dealer will do the install.
The builder would not fit any one other than the standard Jabsco with the order.