Best 845 tube out there?


I am running a pair of Cary CAD-211AE monoblocks with the standard no-name Chinese tubes shipped by Cary. Whilst I am happy with the sound, I think I should buy a pair of 845's to keep as backup in case something happens to these tubes.

Because I will need to buy FOUR of them, this rules out any tube that sells for stupid money (e.g. vintage RCA 845 tubes).

The only current production 845's I am aware of are:

- Shuguang 845 "standard"
- Shuguang 845B
- Shuguang 845C
- Shuguang PSVANE 845
- KR Audio 845

I have found reviews of the Shuguang 845B and 845C, but there is virtually no information out there on the new Shuguang "psvane" 845. Has anybody heard this valve, and is it a noticable improvement over the 845B and C? Also, what do people think of the KR?
amfibius
Hi Guys, I have ordered a pair of Shuguang WE845 to replace my 845B without top mica. 
I am using a Line Magnetic LM518ia. 
Now waiting for the post to deliver the beauties ;) 
@ecll80 Looking forward to your impressions of the WE. I’ve been contemplating upgrading my Shuguang 845B’s to the WE version on my Melody AN845 amp but haven’t pulled the trigger. I have heard though that the Melody amp doesn’t exactly show big differences between the B’s and more expensive 845 tubes. But I do have friends with LM gear that have had good success with the Psvane WE845 making a nice improvement.
I can attest to the many sonic attributes of the 300b, however I also  like the 845 very much. Depending on the speakers involved, some may certainly benefit from the additional (3-4x) power of an 845 output tube. Either tube is capable of exceptional sound quality. 
Charles