Calling all tube heads

I am retubeing my arc ls-16 , and have found some nos amperex tubes, and need to know what will work best in it , an a frame, or a round getter halo ? any clue to what the differance between the two are?
What tube type, 6922?
Are the Amperex you plan on putting in USA, Dutch or other?
What sound are you looking for?
What tubes previously ran in the ARC and what did you like and dislike?
I have 6922 sovtek's in there now , and am interested in 6dj8's made in holland orange globes
I had amperex 6922 (PQ) gold pins in my LS-25 and had nothing but trouble, I called Audio Research and Leonard told me they didn't use Amperex tubes . So that was good enough for me, I just bought a set from Audio Research and now I have no trouble. I can just listen to the music.
I just realized that I ask you a question about your tube type and then failed to respond.

I agree with Autospec about Amperex 6922 Holland, not because Audio Research does not approve, but rather the way they perform in that piece.

If you run Amperex it should be the 7308 US military spec tube, preferability the CEP. This tube is extremely linear, has good microphonic characteristics and has a transparent but neutral tonal balance.

For a warmer sound the Mullard 6922 gold pin works well, and even the Siemens Cca might be worth a try, although it may prove too bright in that piece.

Unfortunately the Sovtek 6922 is not a very good tube. If it were brought in line with their 12AX7 LP, it would provide much relief for the scarce market of 6922, 6DJ8, and 7308 type tubes.