OK let me see if I can shed some light for you, First our stocking dealers have a protected area of 50 miles, if your local dealer did not come up then he is more than likely outside that area, with that being said if I were in your shoes I would be doing business with your local dealer!
As far as the plate exchanger, 20 plate is typically fine but pay attention to flow restriction, if you follow my posts I prefer to use the sidearm system but they both work well if properly set up.
Circs, I use Grundfos on all my installs, typically the 26-99 3 speed, low setting on low demand and high as it gets colder and you see the temp differential creep wider.
What else do you need, Purge ports and temp gauges, don't cheap out as it helps a great deal to diagnose an issue later on.