Easdale just south of oban has all the necessary requirements for your SIB holiday.
Harbour -it may be small but it is one of the safest on the west coast of Scotland. Owned by the community, the harbour hosts the Easdale RIB Rendezvouus every spring
Accommodation self catering and B&B. Info Eilean Eisdeal - the Easdale Island Community Development Group
Pubs -both close to the ferry slips, one on the island and one on the mainland.
Local boating knowledge from the RIB tour operators.
Video about Easdale see
As to some of the cruising potential see
Scottish SIB outing 2015 by the Gurnard
There are loads of alternatives for a wide range of abilities.