chromoly, steel, aluminum? what kind...
for a strut bar, I'm assuming you want chromoly...
Any machine shop will sell u the stuff...
also, go to
http://yp.yahoo.com/ type in metal and you'll find places near you...
FYI: If you plan of fabricating something, but don't know where to get stuff in the first place, you shouldn't be making stuff..
Could be dangerous.. hehe