Welcome to geekhack... sorry for the delay in response to your post. (This keycaps sub-forum is new... not much traffic here yet perhaps.)
Looks like your board has Cherry MX switches, yes? If so, you're in luck as that's probably the most popular mechanical switch for custom keycaps.
I can't speak to the nylon caps that come on the board, but they do sound unique. If you like them, more power to you. One thing to note is that when you get replacement caps, they very likely won't have the same profile as what you're replacing with. So if you want things to be uniform, you pretty much have to replace everything to replace anything. (Aside from maybe stand-alone keys like functions... you could replace the row and leave other untouched.)
Now, as far as where to find keycaps – they aren't super easy to come by.
- The Keyboard Company in the UK sells some, but I'm not sure about swedish layouts.
- There are quite a few sets for sale on taobao.com. But, you'd need to find a Chinese "agent" to buy them for you, and have them shipped. (generally adds a bit to the price.) qtan may be willing to help you out there. PM him, or watch his posts in group buys.
- You may find some on ebay or via a google search... remember you're looking for "Cherry MX" keycaps. They all have a fairly standard mount. (Aside from sometimes your spacebar or other keys with stabilizers I think.)
- Which brings us to the best (but slowest) option, IMO. Group buys. Specifically, geekhack does a big group buy where everyone votes on what to have manufactured from a US plastics company. Once votes are tallied and selections/quantities are made, money is collected and the order is placed. Wait. Wait a bit more. Then they'll ship to someone. (forum boss iMav in round 3) Wait. Wait a bit more. Then they'll come to your doorstep. They had a nordic set in the last round... seems likely they will in the next. Also, they had blank sets just like what you're talking about in several colors. Now, these are textured ABS plastic... not nylon. So I don't know if the feel is what you want, but they're good quality. Warning: Ordering a group buy is the opposite of easy and userfriendly. (no offense 7bit!) He's the organizer, so he may be able to answer questions. Here's a link to the *loooong* order thread for round 3. Also, pictures and key references of what we ordered. Some *cool* keys in there, no doubt!
Of course, much of the fun is finding fun keycaps for your esc key, function keys, arrows, modifiers, etc. You'll find quite a good selection in the group buy, but also
scattered around the internet. (Again, not one particular place with everything you could want... TaoBao is the closest maybe.)
I'm sure that doesn't answer all your questions, but hopefully it helps a bit. I'm certainly no expert, but I do love me some caps. :)
