Tubes for Jolida Fusion Preamp


I have a Jolida Fusion pre which takes 2 12AX7 and 2 12AT7 tubes. Looking to upgrade from stock tubes and request herein recommendations. Thanks.
mesch
Thanks all for the responses. I will check into the suggested suppliers.

As an addendum, I am currently running a Bryston DAC-1 with Audiophileo 2 w/PurePower into the Fusion (Lowrider, I believe you also use the AP/PP converter ) The pre drives a BEL 1001 MK5 which in turn feeds a pair of Esoteric MG10s. My system resides in a tuned dedicated room 12x15x8.5’. I am very happy with the musical experience this system provides. However, as I never owned tube gear I have never had the opportunity to explore the benefits tube rolling provides. Therefore, I think I would like to find a set of tubes that most sonically contrast the Tung-Sol tubes that were supplied with the pre. Looking as much for the learning experience as an upgrade.

Thanks again to all.
There are so many possibilities when using NOS tubes. I think you are mistaking me for another member. But I have been using various tube CDPs and preamps.
My 2 cents as a tube roller is to recommend buying from a dealer with a good return policy (thetubestore.com is a fave) as I've had NOS tubes fail...nice when they're replaced free of charge, and for me a key is buying NOS and not simply OS (old stock) as I really can't trust used tubes unless I'm the one who used them, although maybe I'm paranoid. A fave currently are the NOS Mullard 12AT7s in the phase splitter role in my amp because they explode on start up (what's not to like about that?), and I just ordered a pair of new Gold Lion matched and balanced premium gluten free all natural organic 12AX7s just to see what all the fuss is about (they do look cool after all), and because they're on sale! BLACK FRIDAY man...
Wolf is correct and not paranoid... the dealer must have a return policy.
NOS can mean New Old Stock or it can also mean the tube was used in a
medical or military component in the 1950s for a short time and then was
put on the market for sale as new. The dealer would be unaware and test
the tube and it may still test as new.
I submitted a further response on Friday which has yet not been posted. Yes Lowrider I had mistaken you for another, sorry. Anyway as an update I have decided on the following route:

I have searched the web sites of TCtube, thetubestore, and Brent Jesse and will likely do business with them. The Brent Jesse site was most helpful in describing tube build, nomenclature, and sonics.

Given the possibilities are vast and the price range wide, I have decided that I will call the Jolida preamp person and get his opinion. Barring the result doesn’t influence me otherwise, I am leaning towards purchasing from Brent Jesse a set of GE blackplate triple mica tubes for about $200 a set (all 4 required tubes).

I will update everyone as to purchases and impressions. Thanks again for the advise.

Wolf, can’t believe the gluten free tubes are the fave throughout the Great Plains states.