Re: Amp Racks, shock mount or not?
Shock mounted racks are a lot bigger than regular racks, unless you spend a zillion dollars and get ones like the Zarges models.
In a non-audio application we use these: http://www.zarges.com/en/packaging-transportation-storage/rackmount-cases/mitraset-classic/mitraset-classic-19-housing/ (Don't ask how much they are, you really can't afford them.)
They get airfreighted a lot and the additional size of a regular shockmount container makes the cubic freight charges too high. That was essentially the business case for smaller external dimensions. A few international flights and the cases have paid for themselves.
My general experience is that if you make something look indestructible it will be handled as if it was indestructable. 
I wouldn't bother with shock mounting if the gear is going to be handled by your own people or a show crew. If the gear needs to be freighted and will be chucked about by random people who don't give a ####, then it might be worth it.
