If using a modern regulator/rectifier, my preference is to keep the yellow and yellow/white wires connected at all time.
The Honda twins use a single phase system. Despite the number of wires coming from the stator, there isn't actually anything called two phase. Single phase and three phase are the only flavors.
As for the costs of R/Rs in Europe, I'd be happy to send a bulk batch over. I could do with a European distributor for our R/R.