Here in Australia there is very little choice other than single speed pumps.
Astral Viron P300 3 speed pump about $700 (slowest speed isnt very slow: 1420rpm) http://www.hurlcon.com.au/sites/default ... %20WEB.pdf
@1420rpm 1.5amps 200 litres p/m @3.6metres head (I presume that there would be a fairly sharp drop off in lpm with increased head hence email@example.com).
@2800rpm 6.7amps 302 litres p/m @8metres head
Pentair Intelliflo $ 2000
Zodiac have just announced the introduction of the Zodiac FloPro ePump in Australia.
The rrp will be around $1600 including the basic controller. (although may be less in the hands of the retailers).
Due to the power supply differences, it will have a top rpm of 2830 and minimum of 600 and I guess it will be the 1.5hp
Onga (Pentair) Silentflo SF750 1hp $460 (http://www.onga.com.au/objectlibrary/62 ... omance.pdf)
@2800rpm 3amps 250 litres p/m @8 metres head
Comparing the Viron with the Onga, the Viron at 1420 rpm and depending on the head (say 5/6m for both pumps) it would move about half the water using half the power consumption of the Onga, therefore the running cost would be the same to move the same amount of water. HOWEVER at 2800rpm the Viron would use more than double the power usage of the Onga, when using the vacuum etc PLUS it's $250 more to buy.