You might talk to Terry and Steve at Western Reserve Audio Design:216-521-0900.Roger Sanders had them building a tube amp for Innersound (I-tube),before he departed that company.They are now selling these amps direct.KT-88 based at 150W/ch,I think they are called the 300s.
I know they have moved their business lately,if you try them and can't get hold of them -let me know.They are available for audition.
No,I haven't an affiliation with them.Roger directed my friend in their direction to help fix a NRG amp,since the company no longer exists.