73cuttyspreme, I certainly agree with your choice of gear and your take on what you want sonically out of these fine components. It very much mirrors my own. Your approach is sound. After investing what you have in the hardware it would be a huge misstep to be cheap about valve selection, ridiculous actually, especially given the lifespan of a well vetted set of signal tubes. These offer more to the mix than does a good set of performance rubber on a sports car or dash of spice on a otherwise excellent meal. I have had my two units since before sending them both back to Glenn and Jim for Signature Editions. Now thinking toward Eclipse upgrades...
Bye the way, there are several very reliable NOS tube sources still in business but a note from experience, Andy at VintageTubeServices is a rare gem and a gentleman! I have signal tubes that he hand/ear picked over a decade ago that are still sounding as sweet as the day I plunked done my hard earned dollars for the privilege. If you where interested and couldn’t readily find a pair of RCA 7058s (for the second gain stage), they are commonly pretty cheap when one can find them, but PM me and I’d be happy to send you a pair.
Please follow back up in this thread and tell us what you find and how it worked out. Do this for future readers (as so many don’t bother to do).