Greenbuggy

Hi I'm Kris and I do sandblasting normally, but am looking to expand my available services. I'm mid-project re-powering an older 185 CFM GD portable with an isuzu C201 diesel engine, and thanks to someone else's oversight I ended up with an extra running C201 for $24 (thanks ebay!)

This diesel engine produces 28 HP @ 2200 RPM. I'm seriously thinking about attaching a pressure washer pump to this engine, was looking on ebay at item 230324793615, pressure washer pump 5000 PSI 7 GPM requires 24 EBHP

Now, I'm not seriously contemplating starting this project until after the compressor project is done with and making me money, so I'm not dead-set on that specific pump, but I am curious about a few other pieces that would go along with this pressure washing "Rig" if I went ahead with this everything would be mounted on a trailer I could pull with my pickup. There are a lot of hog confinements around here and I've heard that there's only a few people in the state that are setup to pressure wash them, as well with a setup like this I could do wet abrasive blasting and avoid the whole dust cloud..I can also think of a few businesses that would pay to have their heavy equipment cleaned.

I have a few questions/concerns though, here's the ones I can think of immediately:

1) What should I use for an unloader for when I release the trigger?
2) where can I get pressure washer hose rated for 5000 PSI? Most of what I've seen at TSC only goes to 3500-4000
3) The C201 has an electronic solenoid that controls the throttle (basically idle or full throttle). Where can I get pressure switches intended for water service to throttle back the engine when unloaded? Or maybe an unloader with a built in switch to monitor whether its unloading or not?
4) What sort of gun can/should I use with a high output pump like this? Tips?
5) Could I run the pump with a direct chain/belt drive (I know I'd have to manipulate pulley size to step down the engines 2200 RPM to the pumps 1750) or would I be better off using some sort of clutch?
6) any other issues I should be taking into consideration? Anything that would need to change if I wanted to add a "hotsy" style burner?

Thanks