Thank you everyone for your recommendations. I think I will replace my output tubes first, probably with KT 88s or KT 66s.
You could do ^that^ and stop there?
Next step will probably be preamp. Power amps will come after that.
If you are doing the preamp then why even do the KT88 tubes?
Just use the funds from selling the integrated to move to a preamp and power amp.
The KT88 tubes are a dead end upgrade, unless you are open to the idea of stopping there. It the plan is to have more upgrades, then it is an illogical step and a waste of funds.. (But it seems pretty logical to just do that and stop).
The speakers I have are probably my end game speakers, at least until a have to move into an old folks home. Then I will downsize.
This is great - you one piece that is set in stone, and that defines what the power amp needs to do.
If the speakers were in question too, then that makes the problem have another degree of freedom and it becomes wildly complex.