CSA 14 or CSA 28 by Copland - advice needed on re-valving

I have a Copland CSA 28 (same as 14 but with a remote vol adjustment) and I need to replace the two 6922 valves with something suitable. I have the Service manual but there is nothing in there that indicates if they need to be a matched pair or not :scratch: I have the possibility to buy 4 lightly used Siemens ECC88's but they are not matched.

Assuming it needs a matched pair can anyone suggest a good choice at a reasonable price?

The one I had back in the day came with a matched pair of Edicron 6922 (which I was told Copland used as stock for the CSA 28 production run); I believe they are still available on the market.
With regard to reasonably priced replacements, my dealer had recommended the JJ E88CC Gold and the EH 6922 Gold.
Hope this helps.

Thanks for the reply, I'm sterring towards the JJ or EH versions at the moment after reading more posts in various forums.