Tubes for Cary sli80 integrted

hi friends .
after i read in the forum things about tubes for my cary sli80 i dont know what is the best tubes for my sli 80.
i m new in the tubes world so i dont know what kind of tubes is sound really good in my sli80.
i have the standart tubes that came with my sli80 'and i have devore fidelity nines speakers ,and cd of cary cdp1.
pls can u suggest me what will give me good sound stage to my speakers and vocally and not thin sound.
i hear music like rock country and others.
and if the 6922 sovtek tubes made in russia is good or not or better to put anothers tubes that give me alot better sound ? all i know that cary company put this tubes so they know what to choose or this is cheaper tubes that not will bring the sli80 to the amazing sounds ?