[nyschulte]

The size of the softbox is more important than the strobe.
For the color temp of the strobes you could take a shoot with a whibal card at each power change.
The size and thus the proximity of the softbox to the models makes the difference: if you have to move a smaller softbox further away to get the model lit gives you a stronger contrast as opposed to a large softbox very close.
For larger softboxes which have the strobe inside will give you an even illumination with no hotspot.

Nicolas