My machine has a washdown hose already... Pretty simple with a T in the line where the pipe exits the pump on the way inside the cabinet. They installed the T, and then a ball valve that controls a hose, routed to the front of the cabinet... 50.00 would give you a nice setup

I have nothing but bad things to say about Rustoleum!

When it's time I'm going to consult my salesman at Sherwin Williams. Be advised there are different types of Sherwin Williams stores and not all have the same paints or experts.. Here in Houston I have a Sherwin Williams Industrial Coating Store. They have a lot of specialty paints for industry and rough service... We'll see what they say.. I use a special water based coating from them for all my exterior metal painting. It's about 145.00 a gallon but well worth it.

On the sandblasting I'm a little concerned that the metal will be really roughed up by the sand they use. Too rough and the surface will not be easy to clean and chips will stick. On some of the car rebuilding shows they send cars they are rebuilding to be soda blasted.. That leaves a nicer metal condition but I'll bet it's expensive.