Plug into wall is a lot cheaper than the one from Bintel (sorry Bintel).
http://www.jaycar.com.au/productView...UBCATID=999#12
I say, get the jump starter it is cheaper and is the same as the more expensive Bintel power solution (sorry again Bintel).
If you get the jumpstarter then get this one from Jaycar
http://www.supercheapauto.com.au/onl...33#Description
Also what you call portable deep cycle is not deep cycle but just a sla (sealed lead acid) battery like the ones in the jumpstarters.
So get the jump starter and be happy
Or get the jump starter now and a separate plugin power supply later like the one from Jaycar and use that when you have 240V available.
Batteries can be charged about 350 to 400 times and then they loose capacity.