This is maybe the most bewilderingly difficult thing to find a specification on – the Phoenix pluggable terminal blocks that go to Control4 devices. Good news for you, I can tell you specifically which Phoenix part numbers are required for any HC250, HC800, EA-1, EA-3, EA-5 or IO Extender.
3 position block – Phoenix part 1952270
12 position block – Phoenix part 1701334
Ignore the photos – read the specs. Get a few to keep in stock.