Recommend new EL84 tubes

@dekay I also used old Russian 7189 types (later marketed by Sovtek as the EL84M). They were not as 3D, but I still liked them in the Pilot.

Similar experience here with 7189/EL84M.  They were a little softer, not as deep of a sound stage or detailed as other NOS EL84s, but still very nice. I liked them. 

Like others here, I also tried the Tungsram EL84, and it was bit more detailed, and airy, yet not as smooth as the Sovtek EL84M military tube. Pick your flavor. Same with the Tungsram 12AU7, 12AT7s, detailed, not as smooth as PSVANE, or NOS Mullards hoarded away.     

I recommend Anthony at http://www.tubeaudiostore.com/

He's taken over the helm at Music Reference and has select EI and Sovtek EL84M.  I've used them exclusively in my RM10 for over 11 years and Never had one short or wear out.

7189 tubz will give u few more watz

Firstly, thanks to all who have responded.

The originals were certainly reliable and have lasted well and the sensible thing would be to use them again but my mate is asking for something that sounds better. My last experience in a DIY amp of mine was with JJ EL84 which I thought were just OK but not great. Difficult making decisions for a friend especially in a different country where he will be ripped off.

Brent Jesse let me return tubes I did not like the sound of, after he told me to play them for 60 hours to see if their sound changed to my liking.

I chose less costly alternates, he gave me a refund for the difference in cost, happy I am.

https://www.audiotubes.com/

It's not just the power tubes that effect the sound.