hi, actually i recommed electric pump espcially if you r working coz electric pump is a lot faster compare to manual. I have heard some mommies said they took about 30mins to pump, so i dont't think you want to go missing for working for at least 30 mins.
I bought medela electric pump (after my hubby done his research), I bought dual, coz my sister if you only pump one side the other side will tend to leak. So quite wasteful. My sister also bought the medela dual pump but we bought different model. Only thing about this brand, is quite ex, but we bought from amazon.com which is more then 60-70% cheaper then singapore just that no warrenty (warrenty only covers manufacturing defects).
you can just go to amazon and read the reviews on medela pump, for local there is avent preast pump and pigeon breast pump. you can google for the reviews, will still advise you to go for electric since you will be travelling and/or back to office in working because the pumping time really helps alot!