I don't think a quart tank is going to cut it. Even if it might hold the overflow, it won't give you much if any reserve.
The OE tank provides a reserve to make up for any slow leaks. Depending on the leak it can buy you a huge amount of time to detect a problem.
If a metal tank doesn't come with one already, make a dip stick so you can tell how full it is. Many of the aftermarket ones I've seen don't have an easy way to tell otherwise.
No good ever came from dark and spooky. Norville "Shaggy" RogersThe Ogre's Fiero Cave (It's also at the top of every forum page...)