Setting a recumbent up for your size is pretty simple. The main measurement used is the x-seam. To find this, sit on the floor with your back against a wall, and measure from the wall to the soles of your feet.
If you want to be a little more accurate, you can arrange an angled board, or even a stack of books so your back isn’t vertical, but I’ve found that this doesn’t usually make much difference to the result.
With this x-seam measurement, I can adjust your recumbent to approximately the right size for you before shipping it. You may need to make some fine adjustments, so it’s always good to go for your first few rides with a set of Allen keys so you can fine tune it, but you shouldn’t have to make any big changes or adjust the chain.