I realise I am really late here, sorry. I don't know any suppliers here in S.K. I would (I'm Nathan, by the way) suggest contacting Jack Wu at WooAudio to see if there are any distributors. In terms of raw power for high Ω headphones like the DH800, even the WA3 would have enough (and by enough, I mean with no problem at all) juice for the HD800. It all depends on your listening level, but I assure you that the WA3 is loud enough.
Yes, importing usually means really really expensive taxes and then other problems, a few of which I have experienced. I hope you can find a good alternative.