Having owned this preamp twice, my experience and that of many others has been that the Mullard 10M gold pin (12AX7) tube is the top of the top for this preamp. These are rather expensive tubes at about $600 per pair +. My second favorites where the Mullard Long Plate Square getters from the 50s. Just as a point of notation, Mullard did make the 10M gold plates for private label (even private labelled, they are still referenced as the 10M) which is a long lasting tube!
The 12AX7 rolling in the Calypso has much, much bigger impact than the 6922 tube rolling, so I would strongly recommend starting with the 12AX7s.
For a most complete review of Calypso tube reviews, see the posting/review by Agon user: Jadem6
As for tube noise with the stock tubes, I have never had this problem. I did speak with Jim at Aesthetix when buying my first one and was informed this happened over a very short period of time with some suspect tubes. Overall, the noise level of both of my Calypso have been very, very good (not silent), but very good.