Im looking to build up a 5.1 surround system. I currently have 2 b&w 601 s3's. Do i continue to get b&w 6 series speakers as and when they come up for sale? or go for something else all together. I really like listening to them for my music. They are run with a rotel rcd-02 cd player and an rcd-01 amp. Obviously i dont have stacks of cash and budget is a factor. Secondly if i do continue with b&w's is there much of a problem mixing s2 and s3 speakers? thirdly what priority should i give to buying the speakers, i.e two more for fronts, then center, followed by sub? Additional, I have seen a few sets of 601, 602 and 603 speakers on flea bay. the owners state they are only 2 years old or thereabout but are clearly series 2, when did the s2's stop and the s3's start? thanks in advance of any answers at all.