ARC is long running legendary for a reason but. lets face it, impossible to stock all the parts needed forever and in the case of power supply caps impossible, they can go bad on the shelf… The amp can be recapped w modern parts but it is modification work the factory might not want to perform or stand behind or have gum up the flow of work they are prepared to do. There are many audio firms that this situation applies to. ARC life any storied company has flaws and detractors. i wish them well as they make other choices. Hopefully in twenty years time they are happy…..
You have some great components, especially that Ref preamp ;-) my suggestion in looking for soeakers is chat with and visit a few experienced ARC dealers, they will know what pairs well.
Finally how wonderful that the sound and music have you so energized and inspired, should we all wish to do as you !
Jim