Dave, have you seen the arrangement on HO scale Piko multiple units? They use a split articulated bogie design with a built in 8 pin connector. Simple, effective and easy to couple and disconnect. I have some of these if you'd like photos?
I've done the same thing and ordered the 14 coach version as with it being a build-to-order I assume it'll be hard to source additional coaches after production. Better to have too many than too few!
I model HO scale German and Austrian so this doesn't even fit within my modelling scope but I have to have one. And for the people complaining about the prices, have a look at the continental stuff and you'll see this is priced fairly considering the specifications.