Sounds like first rate upgrades. The NAT sounds like a good choice (I read a review)… the 805’s should be a great upgrade to the Thiels. Yes, a couple little subs would really round it out well. We have 5 x 805’s + 2 800 series subs for our home theater. They are great little speakers.
upgrades
at 68years old Audio fever is on the rise again my 1990 system in part in need of a up grade Starting with mp PLINIUS 16 PreAmp with a great phono stage Is being Replaced with a NAT Symmetrical Balanced Tube PreAmp Any Thoughts @nd up Grade Thiel 3.6 Speakers for a pair of B & W805-D3 Due To smaller living space Driven By a KRELL KSA 150 powerAmp can get some Advise