Woohoo! I'm excited
for you Baz!
For Aussie-based online stores, in the past I've had a hard time beating the prices from d-d-photographics as Alex mentioned above. Haven't checked/compared them recently, but suspect they'd still be very competitive.
For overseas-based online stores, I've used adorama.com extensively. Their service is excellent and quick. You'll find their prices are very similar to bhphotovideo.com and amazon.com, so look at them too. Very hard to beat their prices anywhere, even when you include postage from US and GST if it's over $1k worth of gear, which you will be.
That's an important point if you're going to buy OS. Whatever the price is for the gear plus postage, if it's over AU$1000 you'll get hit with 10% GST when it hits the shore here. Usually the courier company, eg FedEx, will give you a call to say your gear is here, but you need to pay 10% over the phone before they give it to you, then they pass that on to Customs I think.
In terms of the gear you're thinking of...
The 5D II is a fine body and I'm jealous.
Macro lens - yep, the Sigma 105, the Canon 100, the Tamron 90 I've had experience with and they're all great. Pound for pound I'd probably tip towards the Siggy.
Wide angle lens - as Alex said, the 16-35 L is reputed to be good, but I have no experience with it. The 17-40 L I have and it's a great piece of glass. There's wider lenses in the 10-12mm range at the wide end (Sigma), but haven't used those on a FF body so not sure how well they go, or if vignetting is a problem etc. Personally, I'd go the 17-40 L on the 5D II body. If you were getting a 50D or some other crop sensor, I'd go one of the 10-20 ballpark UWA lenses.
Tripod - if you search around POTN you'll see that the most recommended starter tripod and head combo recommended is the Manfrotto 055PROB Tripod + 488RC2 Ball Head. It's rock solid, not too cheap but reasonable. I'd go that.
Battery grip - I'd save the money and go without. Some like the feel of them, but they're just extra weight and I only see benefits if you and I were professional photogs doing weddings or events.
"Intervalometer"? Assume you mean a timer remote for your time-lapse type stuff? I've got the Aputure one off ebay, it works, it's cheap, it rocks. Don't bother with the genuine Canon one. Alternatively, and I've been doing this lately, is tethering to my laptop and using EOS Utility. But the Aputure timer remote is useful and much more portable so I'd recommend that anyway.
Flash - I'm not sure what to recommend here. I was going to recommend the 430EX. I started with that too, but the extra power and features of the 580EXII drew me and now I have one of those too. It depends on what you think you might be using it for. If it's just for macro, you don't need much power at all and there's even 3rd party flashes like Sunpak PZ430 that's just over $100 and would suffice. But if you want some more power for portrait or group shots, go the 580.
For macro, I'd thoroughly recommend just sitting the flash on camera and getting a Lumiquest Softbox diffuser. That's the setup I used here. Nice soft light, and cheap and easy to set up. Get the Lumiquest cinch strap too to fix it to your flash rather than sticking velcro on it.
You haven't mentioned standard, walkaround lenses. What are you thinking for that? There's a big gap from 35-40mm to 100mm. You'd probably be looking for something in the 24-70, 24-105 range? Don't be afraid to check out the other Sigma lenses. I rate them, as long as you do your research on which models are good and bad.
Do your research in the lenses section of POTN and also check out dpreview.com - wonderful resources.
That's all I can think of for now. Hope it helps. If you have any questions, feel free to PM or call me - I'll talk your ear off about this stuff. I love spending other people's money - wisely of course!