I'm having both! Lunch wedding for family at a hotel, and dinner wedding for friends at a restaurant.
We have a lot of guests flying in from overseas for the lunch wedding, and they told us they prefer lunch so they have time to fly back in evening, or take the night off to visit Singapore tourist spots.
Personally, I feel lunch weddings have a more relaxed feel, and dinner weddings have a more glam feel, but both are lovely! It mainly depends on how you envision your day(s) to be like