The best way to find out who your local distributor is at the Zolatone Distributor Website
These distributors are generally geared more towards the design community than the end user...if you know an architect or interior designer that can help you, you may have better pricing & results getting the information you are looking for.
The local distributor should be able to hook you up with a installer in your area though, if you don't know a designer.
As far as "sharing" a minimum order, that may have to be done on the installer level as the local distributors are individually operated - in other words, the same painter may have to paint both trailers, as the distributors may not cross territories. Most installers are only going to want to use product they purchased directly from a distributor themselves, for warranty purposes. The distributor probably won't work with you on spliting the custom order...I could be wrong, but my experience is that they generally aren't real accomodating on small orders.
There is also an issue of over shaking the product. This breaks down the colored particles and negates the speckled effect of the application. So with the uncontrolled environment of shipping it, this could create problems as well.
I hate to sound negative, because I love the product. We have it in our trailer and I've used it on commercial interior design projects over the years. It's just, logistically, it could be tough on a small scale, not impossible, just tough...
For a more technical website check out:
Technical Zolatone Website
Good luck ~