Question about replacing 12AU7 tubes.


I am new to tube amps and have a question about the 12AU7 tubes in my Dared VP-300b Quasi Monoblocks. Each of them has a 300b tube and 2 12AU7 tubes.
I would like to have a replacement at hand if a 12AU7 tube goes out (also read somewhere the stock tubes are not that great).
Do I need to get matched pair or even 4 matched tubes?
If matched pairs would I put one matched pair in one mono block and the other pair in the other, or would I put one of each pair in each mono block so they have the"same" kind of tube combo?

Any suggestions about this and any tube suggestions would be appreciated?

Thanks.
utah_dude
Matched pair, or even better a matched quad. As far as actual 12AU7's go I've always been a big fan of Mullards, Amprex, and Telefunken. In fact if you keep an eye on the for sale listings you will probably find what you're looking for..
For your information,a 12BH7,5963,5814 can also replace a 12AU7. So if you find those types matched you can use them.
All ways's replace in matched pairs. I get NOS RCA from Brent Jesse, he has a good reputation with me and others on this forum. Never get STOCK 12AU7's, they don't last as long or sound as good.
Your VP 300B amps have a single 12AU7 driver tube, and a single 12AU7 input tube. You do not have to use the same type of 12AU7 for both positions. You should, however buy two matched pairs. Amperex 12AU7's and 7316's are excellent tubes, as are the older black plate CBS/Hytron/Raytheon 5814's. I would not suggest Telefunken 12AU7's....For some reason, Telefunken made a lousy sounding 12AU7. Their 12AX7's and 6922's were amazing though! Try a pair of the CBS 5814's as drivers, and a pair of Amperex 12AU7's for the input tubes....A great sounding combo!
Thank you all for your input. I apologize for my ignorance, bigshutterbug, but how can I tell which one is which of the 12AU7 tubes. Does one have more influence on the sound than the other?