Bottom T4 of course.
Cloud wrote a good guide on a powerful Commando company, look in the strategy section
His guide, while good, relies heavily on a aggressive playstyle which means early mapcontrol and domination by pushing axis down to the spawn without a moment of peace and such. It ain't exactly well recommended for players who can't use such style and such style can lead to a loss. Dependand on map and team mate. Doesn't work well in 3v3 environment.