I`ve got a very nice 250 Bar at 15L/MIN, the 250 Bar means it compares favourably with lower Bar washers running at higher l/min.
Its belt driven,Honda 13 hp petrol,Interpump WS251 running at 1450RPM. Its unused aside from running and testing. Its from Spit Water Australia and if you want to google it its the HP251,they have a good site at Spit Water(its all one word but this site corrupts it if its written that way).Hers a pic,i dont think its even dear at £950,about £2600 from a retailer.The black tank is a breaker tank so it can connect straight to mains though the design means it draws its own water or i have the pipework/filter to draw out of a tank or barrel.
I`m in York but i`d meet you halfway and it could be run/worked etc.The fuel tank is still full from when i got it and was filled for the first time.
When i did my homework and from experience belt drive is the best.