TBM, I've been flying the Hawker around Europe and Russia for about 9 years now. It's a tough reliable machine. It'll suit Australia nicely.
The TKS is not the worlds best system but it does work. Use the stuff intelligently and in accordance with the AFM etc, you'll be fine and you shouldn't run out.
Where people go wrong with the stuff is not priming it for weeks on end and wondering why the seals etc let go. Also, some folks get super nervous and use it at the hint of a cloud and wonder why the stuff runs out...
If you're going to be operating remotely, carry 2 x 5 litres of TKS 80 (ok for carriage in the cabin) and you're good.