That's a Hypro pump and they do work OK. The one shown has a 2GPM output at 1000#. The beauty of it is you can A) run hot water through it and B) inject soap at 1000#. The only downside I found is, injecting soap into that head kind of cruds up the pump internals, eventually.
That pump has fallen out of general use, in favour of those brass guys, but there used to be millions of them in service.
Stroker....nothing mysterious here. You need a motor (mine is a 1 1/2HP/ 1725 RPM), a pump, an unloader valve (so the water is diverted back to the pump intake, when you shut off the wand), a hose and wand set up. A back flow preventer is also desirable. That picture shows the piping. PM me if you need specifics.
Check some prices and I think you'll be looking at those $300 gas models.
I bought the one pictured about thirty years back from Princess Auto and paid around $800. Oh how things have changed! with those imported goods.
PS...two downsides to those $300 units...can't run hot water and soap is injected only at the lower output pressure. They usually have hi/lo settings by pulling on a collar by the nozzle.
I helped a friends dad build one a few years back. I made quite a few parts for him (no charge) and he STILL had ~2x what it would cost to purchase a good running used unit. Plus it was cumbersome, not neatly packaged and looked very piece together. It worked great in the end but if you had to add up the $ and time invested, so not worth it. As mentioned above if you do it, go with a cat pump. But a 110v motor is not going to give you much power to work with. Good pumps are very power hungry thus most of the larger pressure washers you see are either 220v+ for industrial settings or gas powered.