I got the MD55 for £100 for the main system, and a MD40 for the chiller. Should just about cope 
The guy I got it from said it would happily suck up and pump out pebbles then just keep on truckin. His exact words were “Would you be interested in a pump that would last you 40 years and has an acid proof neoprene/polyproply/(whatever the exact plastic is) sealed head and a magnetic drive?”
Obviously I said yes.
It was interesting finding a coupler to go from 26mm rubber hose to 22mm UK pluming fitting.
The noisiest bit is the fan at the back that keeps the motor cool. The MD40 is even more quiet.