||11-12-2011 12:23 PM
I'd stick with copper as long as water problems do not limit its service life in your area...
Conbraco makes some very nice valves like the Apollo series...
Some of the "Cheapo" valves use a different manner to secure the stem to the ball and are subject to leaks and corrosion where the stem passes through the ball and is tightened by a nut.
The Apollo Series actually has a packing nut on the stem making it a much higher quality valve. Look for a nut between the handle and the valve body to ensure you are getting a higher quality valve rather than one that relies on how hard the button on the bottom of the stem is drawn against the ball.