Got a few questions which might not be related to the topic but here goes anyways :|
Would it be possible to upgrade a little in the future, without going all out - would these benefit from a ±$50 DAC/amp?
If so, could you recommend me something? I really dig Fiio's design FYI.
Are there any European webshops that sell these or should I get international shipping from something like amazon?
Of course. You haven't stated what gear you're currently using, but considering when you're using the new headphones, you will be plugging them to an onboard audio chip, which is terrible, mainly due to implementation but its specs are still very much below what even an entry soundcard can provide.
You have entry products such as Asus Xonar DG, a sub-$50 soundcard that comes with a headphone amplifier, for instance. But honestly, I think you should aim higher and get a better quality source. Of course, this depends on your listening habits, whether it's music, gaming or movies.
About FiiO, you might want to check here: http://www.fiio.com.cn/where/index.aspx