I think building a custom cart is the only way forward.
If this helps - I wanted all my tools within reach of my hands without having to look and I thought the commercially available bases for the truing stands where rubbish.
So I crafted a small base out of wood which my truing stand is now bolted to. It has diagonal recesses for my nipple driver, spoke guage and spoke pliers, and different size nipples inserted using short lengths of spoke for the different size wrenches. The tension meter hangs on a bolt on the side of the stand itself.
I can carry the stand about and set it down where ever its needed.