I need help on Cary SLP-05 tube roll ...

Hi all,
I'm newly own a SLP-05 and just hunted some NOS 6SN7s:
- 4 matched Sylvania 6SN7GT tall glass
- 2 matched Kenrad NAVY CKR-6SN7GT black glass
- 2 matched Sylvania JAN-CHS-6SN7GT VT-231

Please help me pick 6 out of them for tube position 1-6
(headphone tube 7,8 can stay with stock)
- 1 and 4 are left channel gain buffer
- 2 and 5 are right channel gain buffer
- 3 and 6 are L&R balanced input buffer.
Which buffer is most sensitive to tube roll, gain or input ?
I'll use the unused 2 tubes for my CAD120S driver buffer

Thanks
Thuan