The Clare valley is a great option if you love outdoor activities, because you can cycle the Riesling Trail, and visit some of the finest wineries (Watervale Cellars, Skillogalee, Mitchell, Taylors etc)
There are a lot of quality B&Bs with romantic settings, open fires etc etc
In the Clare valley, Mintaro is a quiet little place where almost every building is heritage listed. Check out:
http://www.clarevalleymintaro.com/
Any of the towns in the Valley have a variety of accommodation depending on your budget.
There are also excellent restaurants.
Check out SA tourism's website:
http://www.southaustralia.com/ClareValle…
KI is not a bad option, and if money is no object then here is the latest thing in super luxury eco-tourism:
http://www.southernoceanlodge.com.au/
Still heading south but not on the island are the Southern Ocean Retreats -that would mean travelling for the food and wine, though; for some seclusion and style try the Ridgetop Retreats, designed by Max Pritchard:
http://www.southernoceanretreats.com.au/…