When I looked at the pressure washer selection at the local home center ... I found pressure washers that were either too 'big' or too 'small.' I found the 'perfect' pressure washer at Sherwin-Williams.
I wanted the tool for removing badly blistered / flaked paint, prior to starting over. This task calls for more than what you need for cleaning. Too much pressure, though, and you risk damage to the surface.
Sherwin-Williams offers the Job Pro 2703, a custom model for S-W, by M-T-M. It has both the pressure and the volume you need.