[Formerly YB-2]

Jack - no chart I'm familiar with. Check the listings from all the usual suspects (The Tube Store, Doug's Tubes, Upscale Audio, Jim McShane, etc.). Most will have the same new tubes from New Sensor (Gold Lion, Tung-Sol, etc.), EH, and a few Chinese. However, all will generally have different NOS (GE, RCA, Sylvania, Raytheon and various Europen & Japanese). Lots of tube 'opinions' on places like Audio Asylum, AudioKarma, DIY. You will need to check with McIntosh to make sure about the need for matched tubes. For $5, I generally consider it worthwhile in a preamp. You will want 'quiet' tubes in the phono-section, especially if you are listening to speakers with a 90db or greater efficiency.

Edit: If you call, either Jon at the Tube Store or Kevin Deal at Upscale can generally give you a good run-down on their thoughts about which tubes in your C2500. Both are very knowledgeable, though Kevin will be Kevin. So is Jim McShane, but I'm not sure how 'up to date' Jim is on newer gear like your C2500, as he is considerably more of an 'old hand'.