tube suggestions/ brand new to tubes

Best advice I can give is only use exact specification tubes.    Don’t go on someone’s suggestion,  if in doubt find a resource like a late model  Hickok tube tester owners manual,   

There are charts with exact substitutions , like 12ax7 and ecc83.  One is the US name and the other is European. 

There are close substitution charts too but I would only use exact types.  Tubes that gave the same electrical specs like current draw and voltage.    Lots of date that can help make good, safe replacement tubes without risking damage.  

Another vote for Andy at Vintage Tube Services.  As with everything in life, you get what you pay for.  With Andy, you are paying for knowledge, expertise, and somebody that CARES which tubes are the best match for your gear.  He’s an acquired taste, but I like dealing with no-nonsense businessmen because I was also one.  I want brass tacks and the bottom line, and that’s Andy.

That said, when you wrote this preamp will be in a system playing mostly rock and roll, are you talking about 1970’s classic rock and guitar heavy current rock?  If so, you should talk to Andy about these particular tubes to see if they match the sonics you are seeking:

12AU7 --  NOS Mullard, Telefunken, or RCA.

12AX7 -- NOS Amperex or Mullard.  NOS Telefunken are the best, but pricey.

12AT7 -- Again, NOS Telefunken is the king, but open the wallet and try to find them.  A good alternative is NOS Siemens or RCA.

As others have said, give the tubes you have time to develop a sonic signature before making any moves.  See if they provide a sound that is appealing to you.  If not, or if you want to experiment, start the tube rolling game and discover the excitement of being a "Valve Head".

https://vintagetubeservices.com/

P.S.  You sign off with Robert TN.  Are you in Tennessee?  I was born and raised in East Tennessee and graduated from UT-K.

Like a broken record I will repeat:

Get thee a Tube Tester, otherwise you keep yourself blind.

Test new ones when you buy them. Test them periodically, i.e. every 6 months. If a problem comes up, be able to find or rule out the tubes.

Find shorts (rare but they do occur), weak strength, unmatched strength.

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I might take a chance on one of these

This just listed, not tested, seller has no tubes, 30 day returns,

https://www.ebay.com/itm/267730051303?mkrid=711-53200-19255-0&campid=5338381866&toolid=10001&customid=820ac094-81ea-11f1-83ef-306561363937

tested, works, read the description

https://www.usaudiomart.com/details/650330617-beautiful-heathkit-tc-2-tube-tester/

Unless you find reputable dealer that has NOS stock these days Tung Sol, Sovtek, Mullard (now it's just brand name), Electronic Harmonics are all owned by the same company and most likely made in the same factory in Russia. Not saying the are bad, but it is hit and miss. Depends on the batch, honesty of a dealer. Dealer honesty is questionable as is factory quality inspection. If you do find reputable source for NOS tubes (Telefunken, Amperex, Mullard, Western Electric)save money and go for it. That might be only way that you might really hear the difference. Good luck in your pursuit of sound bliss.

@allenf1963,@hanki      Good afternoon. Thanks so much for your post and education in the field. I listen to ONLY,  Rock and Roll. 60's, 70's, 80's primarily. Best advice I've gotten from all, experience to tubes already in place before deciding on a direction. 

Makes good sense. Yes, to the question about living in TN. Cookeville area, equidistant between Knoxville an Nashville on I40. Great area by the way. Vintage tube services (Andy) comes up quite a bit, in many posts. So far I'm very pleased with the current tube set up. Buffer tube 5U4GB, output 12AU7, input 5751 tung -sol . I do prefer more analytical, detailed, sound stage, and dynamics. (rock and Roll) and that may come with time? But, in the long run my desire is as described before.  I may give Andy a call next week and see what he has to suggest. Would like to at least have a spare or 2, just in case. I need to listen to the Terry London piece, on the Jackpot also. Hey Guys, Thanks for the education. Robert   Ps, also spoke with Aric the other day, and he supplied a few sources also. Have a great weekend all!