I use a Gold Hog Stream Sluice with the two mats and adjustment legs that come with it. It works fine and can be used optionally as a highbanker.
I have considered using a smaller sluice for smaller streams, since this sluice is 10 inches wide, there may not be enough water to run it properly even with the slow water mat. It could be used in stream or as a highbanker with a pump.
It does fine with adequate water and even can be used as a clean-up sluice with the optional power head and a 1100 gph pump.