Was about to pull the trigger on the Sun Joe SPX4000, did a little more research and ran across the Karcher K1700. My intentions are to use a foam cannon and I'd like to know which one I should get. From what I understand, the Sun Joe doesn't use standard accessories....you can only use Sun Joe quick releases, etc. Based on that alone I was thinking that the Karcher is the better machine BUT the PSI and GPM are lower than the Sun Joe. Can I use a foam cannon right out the box on either? Will I need additional accessories? This pressure washer will be primarily for car washing every week and the occasional driveway cleaning. I'm stuck....any help would be great! Thanks