where can i get a harmonic balancer???

ok, i had a problem with my alternator on my 89 lx. first it went bad, so i replaced it (quite a pain i might add). after that the belt came off and found out the big bottom bolt for the alternator had come out, so ace hardware helped me out since no auto parts store had the right one. i put a lock washer on there, so my alternator is great now, but belts keep shredding. now it's my beleif that i go to one of the most honest mechanics in the area, and they showed me the harmonic balancer wobbling and they know i'm a broke 18 year old so they told me how to replace it. that explains a helluva lot. i've looked everywhere, and opposed to a junk yard, i'd like to find a new harmonic balancer, but where can i get one? thanks