Suggestions for my second flash modifier

I'm adding a second speedlight to my collection, right now I have a shoot through umbrella for use with OCF. Would you experts suggest I go with a second umbrella or get something different to go with the new speedlight? I'll mostly be doing portraits of family/friends both indoors and outdoors, and maybe some 'product photography' for ebay etc.

A softbox. Preferably with a decent lip and a grid, will give you loads more control than a brolly, but costs much more too.

Second the softbox. Umbrellas are a nightmare inside when you want to control where the light is going. But they EAT light, so they are tougher to use outside.

Fotodiox EZPro boxes are a great value. the grids are cheap, but flimsy.