Tam, a couple comments: if you listen to music with substantial low bass content(e.g. pipe organ, etc.)then even with the relatively good bass of the M60s, a good sub will be a significant benefit. This is also the case in movies when especially strong low frequency effects(LFE) such as explosions, etc. are present.
On the speaker wire, there's not a scintilla of solid evidence that regular lamp cord of an appropriate gauge doesn't do the job as well as anything, regardless of cost. Although they're not "idiots"(especially if they make money by selling magic wire)and certainly shouldn't call you that, the term would fit them more closely if they stubbornly refuse to acknowledge basic audio principles of power transmission and the results of properly controlled double-blind listening tests. If you haven't previously studied it,
this explanation by a veteran audio professional covers the topic well. As to why such stubborn resistance in this matter still amazingly creates controversy, the concluding paragraph in his "The Big Picture" section summarizes it.
