Tube Rolling Time

I stumbled across (not literally) a little Dennis Had Inspire SEP amp a few years ago and although it requires efficient speakers (which I have), it has 4 tubes...rectifier, input, and 2 output tubes. This means it's a tube rollers dream since there are so few...consequently I have a drawer full of tubes for the thing that could easily last decades, and the really good news is it's the best sounding amp I've ever owned. 

What should I consider next?  Conrad Johnson is on my radar.  Suggestions?

I don't understand. You want to get a Valve amp, so you can roll tubes?
Is there a reason? or just like to tinker? It's all good, BUT if your going to be tinkering, (and you ARE a tinker), you might want to invest in a tube tester and Tinker away...(300-600.00 usd) You can learn how and why tubes sound the way they do, the construct makes a lot of difference..
More importantly, how to make it sound  better (not just different) by matching, and testing..It can make or break SQ by the buckets full, in valve gear.
In stereo amps!!! Balanced tubes go a long way.. Heck MB too for that matter.. Proper Bios is another, little nugget that can really impact SQ. Depends on the unit..

Regards

@oldhvymec

I just want to listen and play with tubes, more.  It’s something I’ve always wanted to learn more about.

Thanks to all of you for your recommendations and suggestions.  I’m learning a lot.

I just want to listen and play with tubes, more.  It’s something I’ve always wanted to learn more about. 

Sometimes it's the music, sometimes it's the gear, sometimes it's both.
It is interesting, is it not? Some people settle for what sounds good, some won't stop till GREAT.  AND there are those, that CAN'T stop, no matter what, good better or BEST, just can't stop... LOL it is a great hobby.. Get a tester, don't spend a fortune, and enjoy all the little tricks of testing, tuning, tinkering, BLOWING UP!! Don't do that test.. LOL

You'll be amazed at what some people called matched, and NOS, you'll really get a lesson in ethics, if nothing else.. LOL

Regards

Suggest you start your rolling journey with the input tubes (small signal tubes). The input gain stage has the most influence on sonics. Next, the driver aka phase inverter tubes, have some influence on the sound. 
Rolling the rectifier tube can have a very audible effect on the sonic signature of the amp.

I'm a believer in using NOS tubes from a reputable dealer.
+1 on Brent Jessee website. There is a wealth of information on the sound produced by tube type and by  each manufacturer.