I have to second Leafs on Coincident. If you were to buy into the new UHS series, the Cary 2A3 would be a great match. Not the ultimate 2A3, but you get a lot back in terms of service, support, parts availability, upgradeability, trade-in value, and dealer network. Assuming you have the sensitivity to handle a 2A3, you may find as I have that it is superior to the 300B. Better bass, glorious you are there mids, and a clean treble. I would get the speakers first, and then move on the amp. That is the way to go with tubes/SET, in my experience. Your Arials are definitely not SET friendly, though they are way too great a speaker to give up on. You may want to keep this in mind; don't underestimate how much you will miss them when they are gone.