I don't wish to be rude but here in the UK the lingerie biz is very good, but the fastest end of the market is in bras for the larger busted....apparently the average size for a young adult female is now 36C and upwards.
That's the UK build, so as Singapore is populated by smaller busted women, generally, why not concentrate on sourcing pretty and functional bras for that market? There are many here in the UK.
You can also get great bras now which make girls appear bigger....ones you can pump up to any size you want. Really.
My guess is they would do well in the market over there.