Any triple can be used as a double - with granny ring, and a 46t or 44t installed as a middle ring (Stronglight and others make those chainring sizes to be used as "inners" - in the mid-position).
This keeps the rear "as is".
I have run a 46-30, and am getting ready to apply the same solution again on another bike. Any 130/74 BCD triple is suitable, no need to fork out a fortune for the Sugino OX901D.
Or buy the 46/30 IRD double direct.
You can go to 46-28 or 44-26 if you like "living on the edge" with the current shifters - or you could deploy a friction shifter for the front with even a smaller granny ring.