I have a lot of reading to do on here and ADV. But the title pretty much lays out the trip. I have two major questions revolving around the start and end of the trip. I don't know if I want to come back to Canada at the end. I may want to stay in Australia. I am 30 now and 31 in June, so a work visa may not be an option anymore. I have to look into that further.
Where do I buy a bike?
Dubai and Abu Dabi probably have KTMs and BMWs and Suzukis. But I have read that I can't import a bike to Australia. Only for one year under a Carnet. If I buy a bike in Dubai, how do I get rid of it? One thing that may help is my brother is in Australia and married to an Aussie, so he may be able to import it under his name, but I don't know if how long I have to set that up in advance.
My other option is buy a bike in Canada and ship it there. At least that way if, after one year is up in Aus, I could ship it back to Canada and have a friend or family member sell it.
Are there any good options for buying bikes in India? Then I wouldn't have to ship it from Dubai to India.
So, Dubai, Canada, or India?

I don't want to muddy the water for you with bad advice but I have heard you can't buy a bike in India although it is apparently legal in Nepal. Australia need a carnet to admit a foreign bike but that might no mean you can't register it legally there. It will probably just cost a lot of money. This site does have a lot of info and seems like a bike forum for grown ups so I think you're in the right place so good luck.
I'm planning on going through Europe to end up in Thailand. So far it's looking like Europs is easy (I have UK passport) Turkey requires a Visa and I hear it's around £10 at the border, Iran is fairly strict but accessible and Pakistan and India are tricky. Everything from Iran onwards want the dreaded Carnet. You have to ship your bike from India as you can't go any further overland until you get to Thailand. I gather Visas are awkward but unlikely to be refused.
My opinion now... I would avoid KTM. They are unreliable and expensive and parts are difficult to get. They're great bikes but built with competition in mind, not daily use. BMW have quality control issues so do your homework carefully. If you're buying something to travel on and it's likely to be an unknown machine then stick to a highly respected bike. KLR650s have a reputation for reliablity although are crude and slow. Vstroms are reliable tourers but not built to handle much offroad use which may or may not be an issue... they are comfortable though. The Versys is an oddball bike worth a second look. It's attractive as the ER6 is built in Thailand so spares are easier to get along the way. I ride a BMW but please do your homework, they are not as good as their reputation and only a few bikes are worth gambling on.
I'm no expert on paperwork but my understanding is that to arrange a Carnet you would need the registration of the bike which of course, you don't have. That might be worth looking into.

after reading your post and others on here it's looking like KLR is my best bet for what's available in Canada. (It seems the tenere 6-- is the best, but we only have the 1200 coming here this year - big displacement is an addiction over here). I still have lots of time for research.
The CDN government website recommends against going in Iran and especially near the Pakistan border. But everyone on here seems to think it's ok. And since Burma is out now, I might as well see what Iran is all about.

Your plan & itinerary are confusing to me. Nevertheless, my suggestion is as follows- If you are in Dubai, you can buy a bike there. It is 'relatively' cheap. You can then ship on Carnet to India since its closeby, sea shipping should be cheaper faster, while the carnet formalities are very easy (I shipped my BMW R1200GS on carnet from another country- Saudi Arabia to do a South India trip (had a blast with it!) and my clearing agent in Cochin seaport is an expert with Carnets and he especially handles loads of Hummers, Range Rovers etc on Carnet from Indians in Dubai). After your trip in India, you can ship it to south-east asia and later ship it back to Dubai. Once back in Dubai, officially sell it off to your brother in Australia from Dubai (export formalities in dubai are pretty straight forward & simple). Ship it off to your brother.

Forget about buying in India, not only is it complicated for a foreigner to buy, the custom duties being steep the approx prices at the official dealers in India would be as follows:
US$ 48,500 for a BMW R1200GS
US$ 22,000 for a Suzuki Bandit 1250
US$ 33,000 for a Yamaha R1 or Hyabusa