I'm thinking something that is relatively easy for them to do, where the moulds already exist and it's just the colour that needs changing - like SAF set was last year. So who do we have 25th figs or vehicles of that they could repaint? I'd guess they'd always avoid the ones that are too similar to their main figs to protect the main toy line, so that would sort of take us away from Red Laser or Red Jackal.
Snake armour is there still, but that's a bit too Cobra I'd say.
SAS figure would be very easy for them, and would keep the SAF thing going. Beaver with Silent Attack? Do they do a modern style
Stalker with a black VAMP?