Okay, so we are ruling out United, RCA and Amperex due to high cost. Forget about the KR845, they won't work in the 211AE. The Shuguang 845C has a lower disapisation rating than the standard 845, therefore, you will need to adjust the bias on the 211AE 845 tubes. I am not a big fan of the 845C in the 211AE.
Try and find a quad of the limited production metal plate SuperTnT 845W Noblemans which are absolute awesome tubes, but unfortunately, the production run was limited. NOS Cetron 845 also works nicely in the 211AE. I have not tried the Psvane 845, but the over sized glass and build quality looks interesting, but they have not been proven in the field as they have only been on the market for a couple of months.
The Shuguang 845B is the general tube of choice for the 211AE, notwithstanding NOS.
Try and find a quad of the limited production metal plate SuperTnT 845W Noblemans which are absolute awesome tubes, but unfortunately, the production run was limited. NOS Cetron 845 also works nicely in the 211AE. I have not tried the Psvane 845, but the over sized glass and build quality looks interesting, but they have not been proven in the field as they have only been on the market for a couple of months.
The Shuguang 845B is the general tube of choice for the 211AE, notwithstanding NOS.