which softbox would you get?

I have 2 Interfit Stellar mono lights and 2 softbox around 39"x39". I want to get a smaller softbox for head shot and easier light control.
Which of the following is a better choice.

Cheapest.....
http://www.bhphotovide​o.com …4x24_Stellar_So​ftbox.html

Looks decent but require adapter ring. I can get the one from my other softbox but I'll not be able to switch to a bigger softbox as easy.
http://www.bhphotovide​o.com …Range_Softbox_2​4x24_.html

It's a little bigger than I want but with modifiers.
http://www.bhphotovide​o.com …box_with_Grid_S​trip_.html

I would go with the 24x36 w/ modifiers- best bang for the buck.
I use the 39x39 for head shots - you might try moving it forward or back -
can make a big difference in light quality and falloff. Not closer but parallel
to model.

The ceiling of my basement is not that high. I hope a smaller softbox will be easier to use when I want a higher angle.

viodea wrote in post #6886536
I have 2 Interfit Stellar mono lights and 2 softbox around 39"x39". I want to get a smaller softbox for head shot and easier light control.
Which of the following is a better choice.

Cheapest.....
http://www.bhphotovide​o.com …4x24_Stellar_So​ftbox.html

Looks decent but require adapter ring. I can get the one from my other softbox but I'll not be able to switch to a bigger softbox as easy.
http://www.bhphotovide​o.com …Range_Softbox_2​4x24_.html

It's a little bigger than I want but with modifiers.
http://www.bhphotovide​o.com …box_with_Grid_S​trip_.html

The first one is absolutely a POS, the white baffles aren't treated to eliminate fluorescence which results in ugly magenta color casts I have one (received as a gift), I would avoid it at all costs. I don't have any experience with their pro line though.