DNI for Dummies, ...or "I need another dataport like I need a hole in my head." Options

[MikeKozar]

I'm working on headware packages for some corporate NPCs, and I'm having some trouble determining what item does what. I think the line that's giving me the biggest headache (no pun intended) is "Datajacks also allow users to
slot and mentally access chips, softs, and BTLs." That suggests that a Datajack is capable of producing the full VR experience of a Sim Module - however, the Datajack listing also mentions adding a Sim Module to it at additional cost.

Here's my question: When looking at the Control Rig, Datajack, Sim Module, and Implanted Commlink items, how much overlap in funtionality is there? Each item would seem to require some sort of DNI, but it's unclear to me what the limitations of it are. Can my Rigger run simsense through his Control Rig? Can a wageslave with an implanted commlink gain the functionality of a datajack with the commlink's wireless signal?