Hi Dmo,
My suggestion for a 5 day would be variation of the Mittagong to Katoomba walk. There is plenty of information on the internet, and even a book by Robert Sloss who cleared some of the track.
For a five day trip I would recommend starting at Wattle Ridge, making you way to Yerranderie and then the Kowmung and Kanangra walls before finishing at Dunphys campground to make the trip a little shorter. Have a look at this blog post by David Noble (a member of the forum), which has some good information and photos along with a few suggested routes. My recommendation is that of No. 4.
Highlights of the trip include climbing Baloon Pass, visiting the ghost silver mining town of Yerranderie, camping on the mighty Kowmung river, the magnificent views from Kanangra Walls and the ridge walking of Gangerang and the Wild Dogs.
This website has a video of a similar trip in the oposite direction -
http://fantrails.blogspot.com.au/2013/0 ... g-nsw.html Note however that they took the route along Scotts Main Range which involves a lengthy firetrail and misses both the Kowmung and Kanangra Walls.
Just so you know, this isn't a signposted walk. It covers firetrails, official walking tracks and bushtracks. You need to be competent at navigation and to complete the 120km or so in 5 days, be walking around 25km per day which is achievable with an appropriate start.