I've heard the Vidar in my system and thought it . . . OK. I have PS Audio M700s and while they're excellent I prefer the Belles 350a Ref.
Out of the choices you listed, I'd go with the S300, as PS Audio has been around quite a while and seems likely to continue being around - an important consideration (for me, at least) for service and support.
Out of the choices you listed, I'd go with the S300, as PS Audio has been around quite a while and seems likely to continue being around - an important consideration (for me, at least) for service and support.