I have been thinking about adding pressure washing to my window cleaning. I lost a job yesterday because I did not offer it as a service. So my question is, Can I just get a 2.5 gpm washer from lowes are home depot and change the tips out? I am not interested in getting into commercial just yet with it. I am only interested in eaves, porches and maybe sidewalk/driveway for my residential customers. Would this get me by for 3-6 months until I can afford to go get a 4.0gpm machine?