You wanted to know about Craiguillean. It's a bungalow, which means everything's on one floor. That's good for anyone who doesn't fancy stairs. It's on the island of Seil, about a 20-minute drive from Oban.
The place is right on the water. It's on an unmade road, so you drive down a bit of a track to get there. It's what used to be a ferryman's cottage once, but it's been done up. The main living room is big and looks straight out over the sea. There's a mooring and a jetty if you happen to bring a boat with you.
It sleeps nine but it's only got three bedrooms. That means some of the beds are bunk beds or in the same room, so you need to be happy sharing. There are two bathrooms, which is good for that many people.
The property is part of the Ardmaddy estate. You can walk around the castle gardens. The estate has a hill loch you can fish if you've got a permit, and a tennis court you can use. They sometimes have rowing boats for hire.
For pubs and shops, you need to go into Oban. That's your nearest proper town. There are some good seafood restaurants there. You can get boat trips from Oban to Mull, Iona, and places like that.
Around here, you'll see a lot of wildlife. Seals, otters, seabirds. If you're lucky, you might see porpoises from the cottage window.
Facilities: it's got a woodburning stove, dishwasher, washing machine, wifi, and TV. Bedding is included. There's a cot and a highchair if you need them. Pets are allowed, up to three. There's parking right outside.
If you want to plan things to do, these sites are useful: National Trust for Scotland in Oban and VisitScotland's page for Oban and the Isles.