Do we take it your a traditional window cleaner.
I ask because of its relevance. Initially i would say buy a gardiners back pack, a carbon fibre pole and good brush. Stick the back pack on a trolley.
After a little thought (becomes confusing, sorry) i would say buy a pure freedom trolley system.
Now for the reasoning;
Either way, going down the route of a trolley system and pure water, you will realise like the many of us did, how great, easy and effective wfp trully is. Then you may begin to wonder about using it on your customers windows, not just the hard to reach windows or conny roofs etc.
The gardiner back pack is a cheaper but good quality product, so youve not spent overly much if you then decide (and probably will!) to go wfp. Or you can use the purefreedom as a base unit in a van mount if you again choose to go full wfp, only requiring the added expense of a tank and hose + reel and filtration. So a higher initial cost, but only a small step to take after!
Hope that makes sense!?