For more bass authority you may want to consider the new ET250s which is a new hybrid from cj. I think with the premier 8's you will get more of the same. And yes I believe the later cj products have moved closer toward neutrality. The premier 350 ss would be an excellent choice as well. But you appear to be set on sticking with a tube amp. By the way you have a nice set-up. I too have a 16lsII but with a premier 350ss amp driving Thiel 3.6's.
Chuck
Chuck