In some cases a higher LPM pump may draw less current although there are a number of variables to take into account,as Alex has already mentioned.
It is worth taking into account the effect of the hose, hose run and jets on the actual amount of water that hits the glass. This article looks at some of the points
http://www.springltd.co/node/137Their is evidence that suggests a higher volume of slow moving water will help in terms of time taken to rinse the glass in particular Hydrophobic glass.
On the Converse side the higher the LPM the greater the back pressure can be so it is always a balance between the two.
This pressure dynamics link covers in a little more detail.
http://www.springltd.co/node/138Higher back pressure is likely to cause the pump to work harder and draw more current so again some experimentation will be needed to find the right balance for your system.
A controller can make a big difference to the efficiency of the system as the ability to vary flow to suit the job means the pump is only ever producing the water required at any time. The only limitation with the control in terms of pumps is that the pump does not exceed 10 amps which is the maximum rating of the controllers. Other than this the flexibility of the control means it will run any pump up to 150PSI and rated below 10 amp.
A combination of a tap and controller works well as the tap can act as a water saving device as you move around a building, while the control will DE the pump well before the pressure switch cuts in helping to protect the system and pump from excessive pressure plus all the protection features of the control.
What I personally find very interesting is that the more I learn from you all, and the better I understand what is happening the less I know. Each bit of research opens up new questions as to how and why. WFP is a continually evolving place full of innovation. For me that makes it fascinating to be part of.