Mike it looks like a great deal.
I like the 12 months option. You might like to try Domayn at W.Gos'd.
They may have 18 or 24 months interest free. Worth a look and ask them to match or better your deal from JB.
I use both stores and they do great deals.
If you can, go for the 1gig CF card.
The best prices I've found locally is here. $149 although you'll prob find cheaper on ebay etc.
http://www.eyo.com.au/prod_CC-SDCFU-..._II_1.0GB.html
I get by with one battery for now.
Good luck mate and if you get it I'll have to build that sound switch for you
Cheers