First off, Welcome to AK hearwax.
To answer the question usefully it would be helpful to know what exactly "small" means to you. It would also help to know which continent you live on as that will have a large role to play with availability.
Having said that, I can happily second the Canton GL 260 in what I consider the very small range. I have 2 pairs. One set is used normally in a desktop PC system and the 2nd set are wired in series (so, effectively 8 ohm, as you inferred), sitting on their sides and used as my HT center speaker. Beautiful sounding small speaker.
Moving up in size a bit the Canton Quinto 510 and Canton Karat 100 (nearly identical) are a great 3-way (6.5" woofer) speaker. I've also used some Grundig HiFi Box 650's (similar in size to the 510's and 100's) and they have great sound too.
Going another step up to an 8" woofer (and getting into the upper end of what I consider small) There's the Canton Quinto 520 and the somewhat larger Karat 200. And today I just finished a resto-mod on a pair of Braun L 630's that are in the same general size range as the 510 and 200. With most of the Braun speakers from the '70s one will have to deal with replacing rotted foam surrounds. Also, the Karat 100 and 200 came in both 4 and 8 ohm versions so one has to look closely so as to not buy the wrong type.
All of the above speakers have soft dome tweeters and mids (with the exception that the GL 260's are 2-way) and paper cone woofers and all have a similar clear and clean sound, very neutral to my ears although some people seem to consider them a bit on the "bright side". But my ears say that they just sound fantastic.
ADS was not imported to Europe that I know of so I have no personal experience with them but I strongly believe that they will sound very similar to the above mentioned speakers because they have the same DNA so to speak. Look for some members to pop up with suggestions in that direction.
Cheers,
James