[Varyon]

Disguise kits and the like would be appropriate, doubling as costumes for their performances. If their performances include simulated combat, actual combat skills can also be appropriate. If they previously worked as a stagehand, rope-based traps (using their knot-tying experience from working with props) may be appropriate. If they did work up in the rafters/scaffolding/whatever, they may have solid climbing and similar skills, so climbing gear and grapnels for getting into places cat-burglar-style would work.

Aside from that, Low Tech has an entire chapter for espionage-related gear IIRC, so you’ll probably want to take a serious look there.