nice part of the world, no much to do mind, Tignabruich has a pub or 2, there’s a marina over at Portavadie, there’s also an old abandoned ghost village just to the south over at Portavadie, called Polphail never been though, and tbh not sure if still there, i’d imagine so.
http://urbanglasgow.co.uk/archive/polphail-the-ghost-village-at-portavadie-argyll__o_t__t_1500.html
Getting the ferry over to tarbert is alright, nice wee town and you can take a wee walk up to the old castle too. Was some sort of gala day on when i was there, which was good fun, so probably much busier then usual.
That’s about the extent of my knowledge of the part of the world though. Guessing you’ll be able to cobbler some offroad stuff together the kintyre way and the the cowal way, plus there plenty of forest track to explore if you look on the OS map, never done them though, plenty of road riding about there.