Like VashHash, I don't have a Street Beat, but I carry a small fixed blade horizontally at 11 o'clock for lefty access. Cross-draw would work just as well, or 1-2 o'clock for right hand carry and access. A t-shirt will hide it and it works great for me. I do make my own foldover sheaths for this, as the pancakes are a bid wide and not nearly as comfortable.
This makes a Mule, Moran or Swick very comfortable. It's not as nice, but still functional for a Temperance 1 or Aqua Salt.
The middle picture shows my homemade sheath versus the factory models. The factory sheaths are great, but the foldover carries so much better.
Here's the Aqua Salt homemade sheath. This also works nice at 6 o'clock if that position works for you. The clip is shown for vertical carry in this picture, but it didn't stay that way long.
42 Spyderco fixed blades and counting...