Ok, let me begin by saying that I have no clue about which frequencies are used in Singapore. That being said, the Note is a quad band phone and will most probably function in any country that uses GSM. The one thing that may catch you out would be the 3g support. You should verify the that the provider you plan to use matches the specs of the phone. Here are the specs I shamelessly copied from elsewhere:
2G Network GSM 850 / 900 / 1800 / 1900
3G Network HSDPA 850 / 900 / 1900 / 2100
To answer your other question: Yes, you should be able to change the UI language to English (or a large collection of other languages) although you will need to understand enough to find the correct settings. Usually this is not a problem though.
Hope this helps...
Regards,
Eric Ritchie.
