Yes, you will need a RKL system and an ALC module. I don't know of any of the systems coming with the ALC module.
The Archon can use the same modules as the RKL/RKE with the exception of the NET and RD1 modules. The RKL/RKE he'd units will not work at this time but DA plans on firmware to make them into a remote display on the Archon. The NET is not needed as the Archon is already web based. SLX module not needed it is built into the Archon head unit along with 4 0-10 volt outputs, 2 PWM outputs and 4 switch inputs. Two of the 4 0-10v outputs are the same connectors as the APC module and will hook to the DCI module. The SLX will work with the Archon if you need moe pH or ORP inputs.