Gemma even if it is for the occasional custy you will have to take care with that one, its for domestic use so if you do get it then only run it for 15 minutes maximum then turn it off for 10 minutes, I learnt the hard way so I'm happy to pass on my findings.
Also check with northern tool regarding the fittings from the lance to the PW, it will also pay you to get an extension high pressure hose because if you don't you will be moving the pressure washer around constantly and with no wheels it can be cumbersome and heavy.
You will also need the nozzles and the gutter cleaning attachment to go with it, go for the pack of 5 Use the yellow (narrow Jet) to clean the internal of guttering, the black one to apply your detergent to the out side and then the yellow to clean the external of guttering facias and soffits, do not use the yellow to clean the external sections until you get the hang of it and don't use it if they have wooden facias or you'll blast the paint off.
HTH