Hi,
Im Singaporean so i can help you out here. For chain model shop, u can try HOBBY POINT. There is one in Tampines, Century Sq Shopping Mall, To floor, besides the cinema. There are also another one at Suntec City as well as the main store at Tiong Bahru Plaza.
Another one that bring in some cars is Mworkshop located at Sunshine Plaza, Middle Road, near Nanyang Academy of fine arts.
There is one in Orchard, far east plaza, hobby focus if im not wrong. Havent been there for a long time.
Lastly, theres another one at katong shopping centre, Morgan Hobby, 2nd floor.
Hope these helps
Roland