Safety equipment for a pressure washer
Unless you are unusually clumsy, the extraordinary protective devices you've listed would be excessive.

Eye protection in the form of safety goggles or safety glasses would be appropriate. If the debris you are blasting is at or above eye level, your clear plastic shield provides sufficient protection for your entire face. An ordinary ball cap for head protection takes care of the top.

If you don't care about being soaked by the water, long sleeve shirt with a button up collar and suitable long pants and boots will protect the rest of your body. Hand protection by gloves of almost any type (other than latex or nitrile) will do the job well.

If you wish to avoid being soaked by the spray, there are inexpensive Tyvek brand full body coveralls, equipped with hoods that will shed water. I've used them to operate a weed eater and avoid the "back-spray" of vegetative matter from the cutter. It would be well suited for use with a pressure washer in the environment you describe. All that would be needed beyond the coveralls is a pair of gloves, as the suits include built-in booties.

The bounced spray has very little power. I've been struck in the face with bounced spray and it has approximately the force of a strong rain. You may already be aware that the direct force of the spray can cut skin. I can confirm that.

I suspect the biggest danger to which you will be exposed is debris and gravity. If the debris is small and the distance is short, neither item should be much of a factor. The air space under a Tyvek coverall and the fabric will absorb much of that energy.