Ok thanks Rick, so that's about where I thought you will be, around $10k by the time you add panels, wiring and a proper container/box to attach to that dolly which, if you think about it, is a bargain given the components you chose.
By proper container/box I mean; I've always been of the mind that a mobile (carted and on wheels, beit horizontal or vertical) system is inherently flawed for one basic reason ... it is vulnerable to physical damage. And while a system such as yours is not likely to be easily tipped over by kids playing or big dogs rough-housing or earthquakes or storms ... there is that possibility should you choose to transport it in your truck to another location or even moving the unit up and down stairs from inside your home to your garage for instance.
With that in mind, fully protecting (by enclosing) all components raises the issue of heat build up. So the casing would have to be designed to vent the heat or to be fully opened/exposed when in use. Energy ingress/egress points would need to be cut-in to allow for outlets, input jacks, controls, switches and meters of various kinds as well as air intake and exhale vents and the fans to move the air.
All of this would also lessen, to some degree, the chance of fire due to whatever ... melt downs, heat build up, sparking, flammable gassing fumes building up and igniting, whatever. Whereas wood is both inherently heavy/bulky and flammable and subject to structural failure over time ... plastic or sheet steel would be lighter in weight and non-flammable and provide a more stable attachment surface, especially for components that are hung vertically.
I can only imagine that, during your process, you have already taken all of this into consideration? If so, do you have plans for protecting your components from potential damage? Have you seen any existing cases or tubs or boxes that might work ... anything your set-up might fit-inside-of and still be rigid enough to hold the weight and keep everything securely attached?
Forgive me for the off the wall question ... it's a personal concern of mine that I am trying to find a solution-for in advance.
FWIW I am so enamored with your set-up that I've already begun planning and budgeting for almost the exact same list of components and now I'm ready to approach a local welder I am friends with to see what it might take for him to cut, from stainless, and weld-together a suitable wheeled box that will hold and secure everything and still remain waterproof, shock proof and coolable (sic).
Any ideas you might have already explored would be greatly appreciated. Thanks Rick