Lamm LL2.1 Tube Recommendations?

So I've settled on the Brimar 13D5s and replaced the EAT 6922 with a nice used pair of Siemens CCa that I bought on Ebay from a reputable seller in Germany. The CCas and 13D5 really make everything better. More tuneful bass than I've ever heard in my system. Real Hands touching instruments. Voices smooth and with so many texture layers. Never really understood what a great preamp could do for a system. Wish I could afford more Lamm gear. I'll just dream about it for now.

One thing I've learned, for sure don't bother changing the 6X4. The stock JAN Philips 6X4WA is the best of the 5 I tried.

I am running Psvane 12AU7 T IIs premium grade in the U spots and settled on the stock tubes in the other spot after trying several but the Sylvanias are calling me from their drawer so might have to go back and revisit them again.