I have the ACT2 and the only choices for the 6H30 that I know about are the 6H30pi-EB and the 6H30pi-DR. The EB is the stock version that comes with the ACT2. The DR version is a NOS version that comes out of the original Soviet military batches.
I have tried cryo'ed EBs from a vendor other than CJ along with a quad of the DRs. To my ears there was little discernible difference with those EBs vs the tubes that came with the preamp. The DRs *may* have a faintly greater extended top end. The DRs have been promoted by Viktor at BAT and recently the price has sky-rocketed, as purportedly the last batch of these has been bought out of Russia.
I'm aware of no particular reason to choose or avoid 6H30 replacement stock from C-J versus a reliable tube dealer.
Rgds,
Tim