[Boatanchors] are all 6550's created equal?

[Eugene Hertz]

Hi All, I *might* be in need of a pair of 6550's and I was looking around. Seems that these were very popular with audiophiles.  I was wondering if I bought a pair that were advertised from an audio-related company if they are the same and would work for me (ce 100v).  For example, here is a pair on the eplace that seem reasonably priced... thoughts? epay item# 7340864412

If they are not the same, how could I tell when a 6550 is usable for audio or RF?
thanks
Eugene