I have that exact same bike...same color even. I agree with most of the above posts in that it is unlikely that you need new rims. To remedy pulsation I suggest: 1) clean the rims really well with a mild abrasive; 2) make sure the pads are clean and are not age-hardened; 3) make sure there is no play in the brake pivots (that can definitely lead to severe pulsating and squealing).