I have a 1982 Trek 613 with SunTour Components that someone gave me two years ago. I ride it regularly but really enjoy my kids bike with brake lever shifters a lot. I've been looking for a new bike but a mechanic friend of mine suggested I buy brake lever shifters and the related components and update my Trek frame. I've been out of work and without much cash and this seems like a more efficient alternative. I've been shopping Shimano 105 components after reading on the Forums that is where the quality begins without going over the top in price.
What are the thoughts about adding the new parts to the old frame, which is really good shape, and about the 105s as the group to install? Can it be one, and if done correctly, would the results be positive?