I have never used an Aline power supply, but if it is any good, it would shut off if placed under too much load.
The problem is that some cheaper power supplies, when they fail, will take out the system with it(burn out parts).
It is more then anything about how much 12 volt current a power supply has. It is very doubtful that a 8800GT even needs 100 watts on its own(you still need to run the rest of the system) to run, but many cheaper power supplies will simply not have the needed 12 volt current and instead have more of its power dedicated to its 3.3 and 5 volt rails.
It would be a bit of a gamble either way, but I have run more on less(but my less was an Antec unit).
If you do decide to try this, you would want to ensure you are keeping a very good eye on it.
The power supply is like the heart of a computer, you don't want it to fail, everything replies on it.