I feel that Albert's advice to talk to Mike Elliot is a great place to start. If you like the sound of the SA11, it could be difficult to compromise on a line stage of much less performance. And Mike is in a position to do custom work on a per-customer basis that is just not possible with the big players (ARC, BAT, CJ, Aesthetix, etc.) because of their association/dependency of a dealer network.
Unfortunately, the SA9/SA11 upgrades really make no sense any more with the advent of the Aria WV. For the cost that it would take to get stock SA9 and SA11 models, bring them up to top-upgrade status, the new WV ends up being about 1/2 this cost. Once you subtract the need for the IC and the 2nd PC, the cost is truly a bargain. And from reports by people who owned these full decked-out SA11/SA9 combinations, they have sold them due to the WV's performance. Same designer, a lot of knowledge and experience carried over, but the opportunity for a clean slate design.
I have heard from other designers that have tried to optimize a 6SN7 line stage design and it seems to turn out to be too noisy. I think the desire to use this tube stems from people wanting a different sound/performance than the 6922 tube often used for this application.
And that brings on the value of the WV. Even though Mike has designed the WV's phono and line stages around the 6922, with a flip of a switch, the line stage can run with 7062/E180CC tubes....and let me tell you, this is a revelation...over the top priced pinched waist Valvo and Amperex 6922. For me, there is no going back to the 6922 tube here. The next thing is to look into the 7062/E180CC support for the phono stage.
If you only need a line stage, the WV can be ordered as such for about $1500 I believe. That takes the tube count from 8 to 6, with 4 of these as the power supply.
The size of the WV is about the same as an SA11 but maybe an inch or so less in height. It houses its power transformer in a separate chassis connected by an umbilical cable.
Unlike Albert, I was never able to afford the top Counterpoint models. But I have much experience with the very magical Aesthetix Io and Callisto Signature products after being a long time ARC and BAT fan. And my preamp evolution has recently shifted to the Aria WV. Its simplistic design brings on a wave of new information I never knew existed. And the major reduction in tubes and the multiple huge chassis makes this one of those rare events where something much less in cost and required shelf space result in the next level of performance.
So do yourself a favor, and contact Mike Elliot.
John