As you know, we have the buildlog.net stepper shield from Reactive Substance. We want to sell complete kits too. We ordered good quality electronic components, but the connectors were a little more difficult to find at reasonable prices.
We have everything now except the stacking Arduino connectors (they’re still on their way). I’m thinking of offering the kits with ordinary male headers (the ones on the right in the image) for now; they work fine, but the proper Arduino shield stacking connectors (left) have the advantage that you can use the sockets to make additional connections (e.g. limit switches), using wires like the one in the image.
Funny story: each board needs four four-way screw terminals (for the motors) and one two-way screw terminal (for the power supply). In the quantities we ordered, the price breaks worked so that the two-way terminals ended up costing a little more each than the four-way terminals (those were four times as many). Imagine my surprise when I noticed that the four-way terminals were simply two two-way terminals mated together.