i want to use more water to clean and rinse but i dont want to increase water pressure as i do a lot of victorian sash i was thinking of 4 jets ,this being a bit closer to edge better for frames .also i want to increase the bore of the jets ,letting me then increase the water flow but not the jet pressure.do you think this will work 
thanks
I think you have probably worked it out by now, but as there isnt an off the shelf tool for your needs you may well have to work backwards.
Start at the brush and decide what volume water you need and where..lets say 1L/min to be economical, now lets suppose you want two "jets" near the edges of the brush to clean each side when doing frames, so thats 0.5L/min each. But there are no jets in between so reduce the "jets" volume by 50% and and add another two. Thats 0.25L each for the outside jets both would be 0.5L each leaving A volume of 0.5L remaining for the other two jets wherever you want to put them.
Now look for a pump that will deliver that ammount of water but if you can only find a 2L/min pump that means too much water, you can solve that by splitting the flow so that some of it returns back to the tank, we call it a simple bypass
so that half the flow goes up the pole, but its complicated now because one exit point is higher than the other so you need to restrict the lower flow with a tap otherwise it will starve the higher exit at the top of the pole.
Next you need a hose capable of taking your desired flow up say 70ft, if its too big say 1" then the water hardly exit the jets because of the lack of pressure, similar with a hose thats too long, but if you reduce the diameter of the hose then the pump will be able to cope with it within limits, due to hydraulic pressure and friction/resistance inside the hose. As an example using you domestic hosepipe if its wound onto a hose reel and you turn it on there wont be much flow due to the friction, but if you unwind it then there is more flow, (its almost just the same with a 240v electric reel)
Having got that far you now have to decide how far you want the jets to squirt the water out and the jet diameter, this is where it gets complicated so I just guess
Not forgetting if you want spray jets you will want massive pressure so redesign again.
If I might suggest 4 less than 1mm jets a pair at each end of the brush edges(as you want to do frames left and right and two 0.5mm jets in the middle, using 5mm hose an 80-100psi pump and a simple bypass. BUT you could also have a small on off tap connected to one pair of the edge jets and simply reduce the flow to them alone when not using the brush for frames.
Its somewhere in between having 4 or 6 jets and low flow say 1" arc and one jet with a 26" arc . Hope this helps, just suck it an see.