There are so may typefaces and so many keyboard layouts out there, so I think there´s serious potential in collecting a wide array of them.

Personally, I´m more focused on the machines themselves, but inevitably variety happens. I prefer Spanish keyboards because Spanish is my mother tongue and they´re quite versatile. You can write in quite a few languages with a Spanish keyboard, but not the other way round. But even if I prefer a certain type of layout, Spanish keyboards make up to approximately 40 % of my collection. In terms of layouts, so far I have...

- Spanish: Olivettis and Olympias are a big part of this, and of course the Spanish brands like Amaya, Regia, Patria, etc.
- Spanish from Mexico: Slightly different, with question marks and accents in different places.
- English: Most of the Underwoods, both Imperials, a Halberg Traveler... But not many more. They´re not that common in Spain.
- German: The other big horde, but with many slight variations. Very common in pre-70´s typewriters, and somehow German models are always presend as antiques everywhere. I fear the day I´d go to Germany, because I´ll need a truck to bring all the typewriters I´ll get.
- Swiss German: I´d bet my Remington 10 has a Swiss layout, but any confirmation would be welcome.
- French: Common in Northern Spain but hard to use. AZERTY is a nightmare, numbers and symbols have swapped shift positions... Mistakes guaranteed.
- Swedish: A Halda P and a Gossen Tippa. A bit harder to use than regular English layout.
- Russian cyrillic: Just an Erika 42 with cyrillic keyboard and JCUKEN layout (the most common one). I got this one just to have something exotic because I don´t speak Russian.
- Japanese: Fujitsu Oasys Lite-K. Now THIS is exotic.

Arabic and Yiddish typewriters are scarce, and in addition they type from right to left. That makes them extremely interesting!
In Portugal I saw several mind-blowing, nonsensical layouts. I´m not sure if that´s because there was a time when no standard layout was agreed, but I´ve seen typewriters which looked like the keys were randomly thrown on them. The only typewriter from Portugal I have has an AZERTY layout, but a walk through any flea market will probably yield a lot of different keyboards.

The same disorder goes (as far as I know) other languages, and now that you mention Bulgarian, from the /0´s onwards (or before, I should check) the layout changed because several symbols didn´t see much use in everyday speaking.

As for typefaces... Now that´s BIG. If you take a look at any catalog from any brand and see how many different typefaces they offer for their models at a certain time you can glimpse how far will that go. Not to mention that every typewriter has its own "fingerprint", that is, all of them have their particularities.

This can get really interesting, but it´s such an enormous thing that it´s better to take it in small parts :D