@Gareth_Tom  Also be aware that some of the cheap dock offers on eBay only include the main dock unit and not a power supply.  In that case, 180W Dell power supplies aren't difficult to find since Dell has been making them for a very long time, and any Dell 180W power supply with the barrel connector will work since Dell has always used 19.5V output with the barrel-style connector, but the cost of that separate power adapter would of course have to be factored into the overall proposition in that case.

@ECharles  There's no WD16.  There's a TB16, and then various WD19 dock family models.

@Gareth_Tom  I would imagine that the setup you're contemplating would work, but just be aware that your display setup would be limited to dual 1920x1200 or single 2560x1440.