this qn has been asked lots of times.. but to save u the trouble...
here's where u can buy:
Crumpler Shops (fixed prices, which can be found on
http://www.crumpler.com.sg/)
Wheelok Place
Raffles City
Paragon
the last place: TK Foto (cheapest)
to fit the 70-200mm, most likely u need the backpacks... u could squeeze it in the 7 mil, but not mounted.. or it'll be hard to fit anything else.. check the crumpler website.. they have photos to show u what u can put in each bag...