The Hotel Portsonachan is located on the banks of Loch Awe about an hour's drive south of Oban and is reached by another of those one lane B roads, the B840, off the A 816, the main Oban to ochgilphead road.
If serenity, peace, and tranquility are what you want, then I highly recommend the Hotel Portsonachan which offers self-catering apartments as well as regular hotel rooms. It is isolated, however, but the hotel has a really good restaurant and pub. There is also live entertainment, sometimes complete with a piper who strolls around playing his poignant music.