Cube Audio Nenuphar Single Driver Speaker (10 inch) TQWT Enclosure

Thanks again... 

@charles1dad

The amp is an Allnic T1500

http://allnicaudio.com/product/t-1500-mk2/

I think without going up to Kondo, Shindo, Tron, separates a secondhand integrated is about where my budget ends which is at around £3500 GBP - $5000 USD

Do you think this would be high enough quality?

@yorkshireman, 
Just saw your post (Watching the NBA champion game😊). 
I believe that the Allnic is an excellent choice. 

1Established and highly respected manufacturer. 
2 High standard built quality chassis construction. 
3 Very high quality output transformers.
4 Robust power supply.
5 Very thoughtful  soft start mechanism. 

This should sound quite wonderful paired with the Nenuphars. 
When you're able/willing to, buy the best 300b tubes you can afford. 
The one drawback to the 300b is the premium level choices are not low cost. In this case you get what you pay for.  

With an SET of this caliber and the high level Nenuphars there's little rationale for compromising on 300b tube quality.  You'll be rewarded.
Charles 

@charles1dad

Another bonus is that it only uses 2 300b tubes. 

Thanks again Charles for all your help and advice.

You are welcome.  I believe that you'll be exceptionally pleased  long term with the Allnic-Nenuphar pairing.
Charles