Ever visited the Singapore Philatelic Museum before. If not, you should!
I have been down there twice and enjoyed both trips. A single trip will take you less that two hours. It has a good postal history of Singapore and also a nice collection of Singapore postage stamps.
The museum is located at 23-B Coleman Street in Singapore and used to be formerly part of the Anglo Chinese School which was completed in 1904. In the 1970s, the building became the Methodist Book Room till it was restored to become the Singapore Philatelic Museum in 1995.
The purpose of the Singapore Philatelic Museum is to promote interest in and the appreciation of Singapore's history and heritage in philately. Besides the permanent galleries, the theme galleries offer a host of changing exhibitions through the year.
The museum also has a stamp shop which has a pretty good collection of stamps. I personally find the stamps abit expensive. You can probably get cheaper stamps online.