Maybe you'll find this helpful: Wedding Venues - Hotels, Restaurants or Outdoor Wedding Venue? . You can read the articles in the link to help you get an idea of different ROM locations. Or you can download the attached file for complete evaluation guide of the different ROM venues in Singapore.
what kind of rom are you gonna do? for me, i'd choose a rom in a hotel. but if you only have small guests for the rom then maybe doing it in a resto would also be fine