Tubes for leben cs600 ?

hi everyone .after i bought my used leben cs600 ,i found that my speakers (devore nines) have lack of details and dynamic.
i thought that the leben is the problem and i considered to buy the line magnetic 218 ia amp,after i got response here in the forum and suggestions that to replace my tubes in my leben better of buying a new LM audio amp (218 ia SET).
i choose to stay with my leben and replace the current tubes that are :
4 - electronic tube 6cs7 (made in usa)
1 - sylvania 6cj3
4 - goldlion kt-77 genalex made in russia.
the 6cj3 look black half of her and the 4 pre tubes (6cs7) look old need to replace. i like to replace all the tubes in my leben 9 new tubes but i dont know what to order for the best resault and to slove the details and dynamic problems ?my dealer in israel say all new 9 tubes of original what leben company put need to be in my leben and it coast to me 400$, or there is another alternative to order and what will be the best for my leben ,i still not know from where to order and what tubes to choose and why
please help me this problem, wait for response
thanks alot.