Hi, Michele,
Have you tried the No. 26 by the Sea hotel in Oban? It was recently named one of the 25 best boutique hotels in the world.
Also, you may want to consider Helensburgh, on the north shore of the Clyde, as a town on the outskirts of Glasgow with easy train access to center city. Trains run from Helensburgh Central to Glasgow Queen Street very frequently. The journey takes about 45 minutes. Helensburgh has a slightly more "genteel" vibe than the corresponding towns on the south shore of the Clyde. Unfortunately, accommodation prices will reflect this difference. There are many hotels and B&Bs from which to choose.
Trains also stop at Helensburgh Upper on their way to and from Oban. However, that service is not nearly as frequent, and Helensburgh Upper station is a fairly long walk from the central area of town.
Mike (Auchterless)