Greet overall suggestions here…
But since you’d already mentioned you’re going to get a preamp to run with that excellent Bryston, definitely look into a decent used Rogue audio pre at that money. But there are other brands that do really well at lower cost to offer well designed and great sounding tube pre’s. Van Alstine and Quicksilver come to mind. It would just be a matter of matching with your Bryston.
Tubes are awesome…but there are solid state pre’s that do magical stuff too. I was looking at quite a few different tube pre’s until I tried an SPL preamp. Blew my mind. Holography, stage, depth and a touch of warmth. Not to mention the clarity and separation. No longer want a tube pre - at least not until I can afford a really, really nice one. But a nice SS with discrete components can still get you something special.