It's a little left field, but if you like the long abseils and more open style canyons of Kanangra, then Bungonia offers some good options. A great double that I have done is Spring Creek and Fordham. The first is a very impressive canyon, the second more of a spectacular gash down the side of a mountain. Best of all you can camp on the nice grassy banks of the Shoalhaven River and only need to carry your full pack through one canyon.
I've got a trip report up about it here -
http://fatcanyoners.org/2009/10/16/bungonia-canyoning-and-caving/Otherwise I'd definitely second Dave's suggestion (some of my all time favourite canyons in that mix, and the camp cave at the end of Fortitude is a truly special place that comes complete with a glow-worm filled canyon section next door to explore!
Another nice weekend on the 'Boori that I'd recommend (and which involves a few less visited ones) was Bjelke's Mind, Steep Creek (Bridge) and Froth and Bubble. You could fit a fourth one in on the second day but we were a little lazy (I'd suggest Dead Tree (Dead Log)) -
http://fatcanyoners.org/2010/04/04/bungleboori-south-canyons/Have fun!