Some of the brand have plastic housing for the pump. I bought a Craftsman off Ebay, and it didn't come with the proper wand tip. Went to Sears, and the staff there didn't even know that Sears ever made an electric power washer.
No matter. Went to Lowe's and got a hose and wand for it. When I went to cash out, the screen asked "Is $64.72 correct?" and then the screen disappeared. I was reaching for the screen at that moment. I told the clerk to put the question screen back on, as I hadn't answered the question. He said that he'd pressed enter, and answered for me. That's unacceptable. The computer asked me, not him. And back up the process, so that I can answer the question asked of me. "Well, you got to press yes for the sale to go through, so what's the point?" The point is that the question was asked of me not asked of you. "Well, the only way to do that is to refund the sale, and ring it out again." So, we did. He was not only an uncaring controlling and pushy SOB, but after ringing out the sale again he was a seriously pissed off controlling, and pushy SOB. In fairness, he's an exception. Most Lowe's people are very n ice.
Got the rig home, and tried it out. Turns out that the pressure swtich inside was messeed up, and the eletric body Craftsman didn't work.
Fire up Ebay, and bought a Campbell Hausfield, which turned out to have a plastic pump body. That worked two or three times, until the plastic pump housing cracked, and the unit was no longer good as a pressure washer. I was on a paying job at that moment, and it wasn't really convenient to have the pump crack.
I found HD had an electric, which is called a Powermate 1400. Has a die cast pump housing. After spending about $200 between Lowes and Ebay, I finallyfor $98 got a pump and wand which worked, and have a metal pump housing.
My reccomendation is to look in the box, and make sure the high pressure output threads and pipe are metal, and let that help make your decision. I also store mine indoors, for reasons of cold and freezing.