I use an oto PP with my Ks, now having owned the SE version I know its a rounder sound with a slightly more forward mids but my opinion is that Ks prefer a little but more power to flesh out the bottom end. However my room dictates that my Ks are at least 12" from the back wall so that might explain that. Maybe if you plan to use your Ks with a wall behind them, they'll be spot on with the Oto.
Oto and Js is superb and don't need a big room in my experience.
I found the larger bookshelf ref 3a's much better speakers than the veenas, but I never tried them with an oto. Think I had a leben at the time.
Jake's suggestion of WLMs is a good one.