tubes for Kora Galaxy Reference

In this amp, I have Sovtek tubes throughout, and was hoping that someone could advise on which tubes (current production or NOS) work well. Would Svetlana be considered a worthwhile upgrade over Sovtek for the 6AS7G? Between the 6922 and the EL84M, which one is more critical to the sound and would thus provide the greatest benefit of rolling? Is it critical to use "EL84M", or can regular "EL84" be used as well?

In my system, the amp has good clarity and detail, but is a bit dry and lean, and lacking in musicality. Looking for a fuller more enveloping sound w a bit more "flesh on the bones", and better involvement and emotional "pull". Speakers are Coincident Super Eclipse; cdp is Metronome CD2V Signature; Manley Control Master preamp; all Coincident cabling.

Thanks for the help.