Along the same road, I believe most people would go for the famous gelato shop near the red house.
But if you want to have alternative choice of gelato, I definitely recommend you this hidden shop inside Katong Shopping Centre at the basement.
Very limited seats but they served some good gelato flavours as well.
Here I have their new flavour, smooth and creamy taste of tau huey; the familiar taste in Singapore.
Tasted pretty sweet but not too overwhelming, and it is dairy-free.