How would this interaction work if I had a Viktor, Leader on the board? I play a Jayce, Man of Progress using his ability to target and kill a Patched Porobot on my board to play another gear from my hand. Because Patched Porobot is both a gear and a unit would killing it trigger Viktor, Leader and let me play a Recruit unit token?

Yes — Viktor, Leader triggers and you get a 1 Might Recruit token.

Patched Porobot is both a Unit and a Gear, and per the multiple-types rules it keeps all the properties of both (Rule 178.1). Jayce's "kill a friendly gear" instruction resolves and sends Porobot to the trash from the board — that's a kill, so the permanent's death is a unit's death. Since Porobot is a non-Recruit unit you control, Viktor's "when another non-Recruit unit you control dies" condition is satisfied, and Viktor is still on the board to see it (no simultaneity problem here, unlike Viktor dying alongside another unit).

Timing: Viktor's trigger is placed on the chain as a pending item while Jayce's play effect is resolving, so it finalizes and resolves after Jayce's ability finishes — you play the Recruit token into your base, and you can still play the gear from hand any time later that turn (per the Jayce clarification).

One note: the Recruit token itself won't re-trigger Viktor, since Recruits are excluded from his condition.