Mains switching pumps

We already had 2 x 2500ltr tanks, so all we needed was the pump to provide rainwater to the toilets as part of our energy star rating. Most builder's spec the Davey Rainbank series, in our case a KRBS2 internal pump. The internal pumps are used to reduce noise and may last longer as they are a sealed unit? I still wasn't certain which particular model I wanted based on capacity and whether it should be an internal or external unit in the event of maintenance, warranty, etc. A quick search and I came upon these comments on whirlpool.

The mains switching should not be electronic, in the event of a power failure (very rare) and the electronics in current systems tend to fail.

The AcquaSaver water diversion is hydraulically operated and seems to fit the bill nicely.

Claytech engineering partner their pumps with the AcquaSaver so I began to look at their CMS5A until I realised it's the same unit as a Leader LMS5A. Leader are sold by Bunnings, so I will get a friend to place a special order.

UPDATE: I overlooked something obvious. When flushing the toilet at night, an external pump will be noticeably louder. We've ordered the Leader LMS 6A internal pump with aquasaver water diversion and mounting plate.

Leader LMS 6A