During Christmas holidays I visited Dayens and we were talking about building a headphone amp from Ampino, which should be rather straightforward operation. Dejan D. (owner and designer of Dayens) told me that something like that will probably happen in a near future. He already has several people interested in a such product, so he will probably go for it. The only remaining question is whether to keep the output power at 25W or to reduce it mainly by using smaller PSU and maybe different transistors at the output. That will also result in a reduction of the costs and the end price, which will make very competitive product on the market.
Concerning the dealer question in the USA: you have one ! Please take a look into his site for the complete and actual inofrmation about Dayens dealers worldwide.
When he makes the prototype, I will have the opportunity to hear it. And if the price is going to be as he mentioned, I will go for it. Although I already have two headphone amps ... As far as I know him, it will though take some time ...