Yeah direct from SP is expensive and you'll probably get hit for customs on top of that, ISO-UK is hard enough to get let alone Spanish and adding dvorak to that I think it's safe to say you're not going to find what you want.
When it comes to blanks but that usually means either DSA or G20 (all caps the same height, would look and feel weird with your current mods) or thick PBT caps which aren't going to be translucent, and you'll probably have to buy a whole set...
Thanks for your help suicidal_orange

Yes, I assumed that I wouldn't find a Spanish Dvorak keyset anywhere, but I asked just in case. I don't care anyway, I never look at the labels so I started looking for blank, translucent keycaps. From what I've learned, my ducky shine 4 has a DCS keyset, so I'd need that kind of caps. The most close I was to find them was this link:
http://pimpmykeyboard.com/dcs-translucent-1-space-keys-sold-individually/But... they're 2 bucks each cap, I need 30, plus the shipping to Spain... It would be more expensive than a complete keyset, I think. I could buy opaque caps, but it would be a shame to waste the LED capability. I've also seen an opaque keycap that has a little translucent dot or square, but I can't find a pic just now. I guess those ones would solve the problem too.