You may also want to check if a Commissioner of Oaths is what you want.
Once you do find one, the only thing that matters is price. Some want $40 per page... in the US, many notaries offer this service for free or a nominal fee.
You can search here for at least a partial listing.
http://www.yellowpages.com.sg/newiyp/
As I close though, by rights the university should provide the notarized transcripts. After all, you are asking the notary to attest that the transcripts are unaltered university originals and how can he know that unless he received them from the university directly?
Possibly, you should have the university send copies of the transcripts directly to the universities where you are applying. This is very common (and required) practice in the US.