As a small engine mechanic for 30 yrs my take is that the engine is not as important as the pump. Sure Honda is probably best but only the GX (commercial grade) not the GV (consumer grade). As for pumps, the pressure should not be the factor that sways you. Sure a pump may claim 3000 psi but if it only pumps 2.2 gpm it wont have much cleaning power, especially for large surfaces. For a 6HP engine go for at least 2.5 gpm, the higher the better. A good Italian or US triplex pump like Cat, General, Comet, Giant, AR all have parts available can be repaired. The no-name stuff from China that you can't get parts for are disposable. A rotary turbo nozzle will also maximize the cleaning path.
