At various times in the odyssey I've gravitated to several components from a single manufacturer(first BAT and more recently Pass), but this pretty much ceased after discovering that almost anything can be improved or successfully re-voiced with DIY modifications. As to cables: once the speakers and electronics have been brought up to a high level, a carefully researched DIY recipe with pure annealed silver wire and branded terminations is the finishing touch. My greatest regret in the hobby is an expensive drawer full of commercial cable purchases.
I can't think of a single manufacturer with whom I would buy into the construct of single-sourcing purchasing-- including Linn, ATC, and Naim.