Are you sure it wasn't a sprayer you were looking at? You can use a sprayer the same way. By disconnecting the spray head at the wand tip you will just have a stream of water come out. They make sprayers in backpack versions, and wheeled versions.

I found it , It was called a water wagon, holds 3 gal. and is pressurized, comes out like a shower head. Thanks anyway tho. It was at a co. called Northern tool and was 59.00. It really looks like a water saver and a back saver.