With this wet sandblasting kit, you will need a pressure washer with a minumum of 3.5 gallons per minute output in order for this kit to operate correctly. For your application, I would suggest using around 2600-3000 psi rated pressure washer.
You will also need to purchase a nozzle for this kit in order to spray the sand and/or media. They are located in our wet sandblasting section under the accessories tab. The size of nozzle you need depends on the type/size of sand that you use. I would recommend that you go with a normal to fine round silica sand/media. In addition to the nozzle, the only other item you will need is either a bucket or hopper to hold the sand.