Assuming that you are potentially coming to Qatar on a senior western expat package then items to be considered are as follows;

a) Basic Salary
This should be similar (or a little higher) than your current (gross) salary. The advantage to you is that it will be tax-free. It is usual practice that it is payable locally - you might want to check with a financial advisor if there are any restrictions on repatriating monies to Australia.

b) Accommodation Allowance
Either the company should provide accommodation of an appropriate standard, or; give you hotel-based lodging until you find accommodation. How much? 9,000QR for a 2-bed apartment, 12,000-20,000QR for a villa. Prices vary by about 2-3,000 depending on the level of furniture.

c) Vehicle / Vehicle Allowance
You can buy a Hummer for 2,000QR/month. Cars are cheap here, but still, not free.

d) Furniture Allowance
If you rent unfurnished it will cost you (say) 30,000QR for your wife to furnish it. Some companies provide an allowance.

e) Education Allowance
Whilst you don't know how long you will be here, it would be appropriate to include provision for education in your contract. Schooling here is expensive, but can be good (I don't know the numbers, though)

f) Flights
Legal requirement is one return flight a year. Business class is nice on long-haul, although Qatar Airways isn't bad. You may be able to negotiate this up.

g) Holidays
It is usual practice to have one month annual leave, with 10 paid public holidays. Do confirm.

If you have any other queries do feel free to send me a PM.

Good luck!