By gig in a box, do you mean your guitar/backline or tape machines effects? Or do you mean your foh or mon rack?
I'm sure you've checked, but the weight of a box like this when confronted by stairs or awkward load-ins can be very heavy.
I switched to individual skb boxes and wheel boards for this very reason.
Didn't wish to sound negative, but in some circumstances an all in one solution can be more hassle than helpfull.
Feel free to shoot me down in flames if you've already been through the design stage and this is exactly the way you want to go.