Hi Jon,
no we already had our Honda Petrol PW and had no problems getting the connections to fit. We went to our local pirtek branch who sold us the hose and two end fittings to connect the lance to the hose and then the hose to the PW.
Here a few pics of how ours came and the blue hose and connectors they fitted.
I dont have any pics of the PW end and connectors to show you but would be very surprised if you could not get it done.
Perhaps its just a case of them trying to force you to buy their PW's when you can modify them to fit most fittings - Hmmmm.

Hope that helps Jon.
Sarah