Many thanks for these responses. I'm bad enough at managing my BA miles, so am a little hesitant about having to juggle another set, and definitely don't want to be applying for credit right now, but thanks for the suggestions.

The OW Visit Asia pass sounds ideal - definitely up for a NRT-ICN-HKG trip (never thought Korea was an option, and been desparate to get back since visiting in 2002). Although in its Y, our Gold/Silver cards should see us okay for lounge access.

Just waiting for the confirmation that I'm going so I can get this booked now