That will be hard to find since rubberdome/scissor switch keyboards usually use membranes which cannot really do NKRO. The Microsoft SideWinder X4 is a scissor switch board with almost NKRO (I've found somebody saying 26 KRO), but it does not have the island style keys you want.
I don't think what you want exists. Maybe try a board with MX Reds, they're really light so maybe you wouldn't mind the increased travel as much. The keys being higher has the same effect as island style keys as there is more of a gap between the keycap surfaces.