LOL I wrestled with the same thing, but decided on the unpowered V12 so I'd have more options on the power amp side of things.
That's the path I had been going down, but I've done some re-thinking about the self-contained Power V12. Both solutions net out about the same for cost, assuming a used Bryston and a new Tannoy. Here are some thoughts on each. . . .
V12 / Bryston 2B-LP-Pro versus Tannoy Power V12
I assume the Bryston is a better power amp than the class D amp built into the Power V12. However, the internal Tannoy amp also comes with a processor and optimizations (i.e. eq corrections, etc.). You can add a Tannoy processor to the Bryston configuration, but that increases weight and adds cost. I'm not sure how to really call this, but I suspect the Power V12 may come out a bit ahead.
Weight is a concern for me. I'm 51 and my back's not great. Staying under 35lbs would be great, and 45 to 50 is starting to push it for me. Putting a Bryston (20lb), AxeFX (10lb) and low end Furman (6lb) into a 6U Gator rolling case comes to 54lbs total. That means I have to move a 54lb case and a 44lb speaker.
Going with a Power V12 means my rack has only the AxeFX and Furman. That comes to 26lb including rack. The Power V12 is 50 lbs. This option has less total weight, and the Power V12 is physically smaller and easier to handle than the 6U Gator rolling case.
Given the important of weight to me, the Power V12 looks like the way to go. However, if the Bryston / V12 combo sounded noticeably / substantially better, I might be persuaded to go a different direction.
Terry.