Any major departmental stores sell these. Try Plaza Singapura,
that store selling travel items. Mustafa and Tampines Mall level 2
or wassit 3.
The first question ever got from bunking with this seasoned
backpacker was, 'When you going to remove your money belt?"
Money belts are very obviously money belts, to a lot of
experienced robbers. That'll be one of the first items they'll ask
you to remove. If you're female, best to remove padding in push up
bra and stuff emergency cash inside. By the time they get down to
your bra, you figure you've got bigger problems on your
ass.
As for cash, carry loose change in pockets and don't bring any
wallet. Shanghai safe lah wah lao eh. Buy the kind of money pack
thingys that are flesh colored and slinged around your body beneath
your shirt can liaos.
Remove padding? 
Actually that was what my friend suggested also.
i am bringing alot of cash over on my first day i beri ham
lar.
