If you have not already done so I suggest you go here and read http://audiotubes.com/
Sorry I can't give any advice specific to your amp/pre combination. But I have had great results rolling NOS tubes in my Cary SLI-80F1. Specifically Sylvania 6sn7wgta's and amperex 7308's with genelex kt88 reissues.
I did try NOS 6922's in my cj premier 16 and did not hear any significatant improvement.
Sorry I can't give any advice specific to your amp/pre combination. But I have had great results rolling NOS tubes in my Cary SLI-80F1. Specifically Sylvania 6sn7wgta's and amperex 7308's with genelex kt88 reissues.
I did try NOS 6922's in my cj premier 16 and did not hear any significatant improvement.