2 cents worth. :)
Seems that you already have a couple 'typical' modelers. Between Silo, Hexagon, C Pro, and Truespace you probably have 99%+ standard modeling covered.
Modo is very good, I understand; but how much really is there that it does, that your other modelers can't do?

ZBrush can do things that none of the other apps that you have can do. It is ideal for sculpting and super high poly count detail work, which you can then export as displacement maps for rendering...

EDIT - Your English is just fine.

Friends don't let friends use booleans.