Seriously though, go Starhub shop if you applying for a new line, show them your 11B and ask for the NSF plan.
If you have existing plan but want to convert, call hotline and request, may need to fax your 11B or something.. Best is personally go down to Starhub centre.
eMarc
singtel also have coporate plan for SAF personnel and is pretty cheap also u might like to check out