If you want speed you can get ADSL 16mbps from the Sonae group (Clix site).
Or opt for NetCabo Pro 4mbps. It says 4G (international) per month but it is unlimited from 9H00-18H00 (Mon-Fri professional hours). This is more than enough unless you download DVDs for a living!
Out of curiosity, why would you people want to 'trade' while in Portugal?
It amazes me that people go to Portugal to 'work' when it is supposed that you should bask under the sun, go to fado houses, eat lots of sardines with top notch wine, go see those crazy fellows who literally take the bulls by the horns (only the Portuguese do such crazy things), ...etc, etc...