It sounds like you are describing a griddle, like Andy says. I have an All Clad one that cost about $100. http://www.chefscatalog.com/(i2tjnf5...dle&item=90005
Lodge makes one but it's cast iron. You will probably have a hard time finding a griddle that's not nonstick.
But -- also like Andy says -- a SS roasting pan would work too.
Technique-wide, though, you need the high sides of a wok (or other vessle) for tradtional stir frying because the sides of the pan are used to prevent burning from the very high heat of the wok bottom.