We are going to start selling the low pressure orifices ($5.00 each) because of our new manifold design. We are going to have a surplus of orifices that can be drilled out. (at least 12 in stock right now)...
for a 3 bbl system they typically use two chillers. The first chiller is water being chilled by glycol and the second is wort being cold by chilled water. The water is recirculated. The plate chillers are much larger and designed to add and remove plates.
The enclosure I posted in this thread had very little room inside. I can tell you just looking at the number of components you have that you are going to want a separate enclosure for all the relays and such.
The port orientation changes from brand to brand. The goal for cleaning is a gravity drain of the wort side after clean-up. I don't orientation is critical for chilling.
if you keep a 1" layer of water on top of the grain a simple hose is all you need. The layer of water is an insulator as well as the hose. That copper is going to drop your sparge water temperature rapidly.
Each chiller should have separate cold in (parallel) and the wort from one to the other (series). The first chiller knock the temp down enough for the second to finish.
We started doing this last year...
Breweries will chill the water with glycol in the first chiller and use that water to chill the wort in the second. The water is recirculated.
How the big boys do it...