Hi
I use Zeiss ZS lenses with my Sigma SD14. I have the Zeiss ZS 35/2.0 and the Zeiss ZS 50/1.4.
Both are good, but the ZS35/2.0 ist better in close-up photoraphy than the Zeiss ZS 50/1.4 wide open. The 50 is good enough starting at 2.8. The 35mm is IMHO already good enough at F2. Let's say I was diappointed with the 50mm wide open. I expected more from Zeiss in this price range.
The 85/1.4 is not available with ZS mount. The only other one which is available with ZS mount is the 25/2.8, which is very good at least what I heard about it. I never used it myself.
I use 2 different M42 adapters. One from Poland, another one I think from Hongkong. No pins on it. I am satisfied with it. The one from Poland is a better quality I think.
If you really need wider than the ZS 35mm and you want to have a good quality, then go with the Sigma 10-20 zoom. There is even a new version out out with different apertures. I do not know the mentioned Tamron.
With teh SD14 and the SD15, it is easy to focus manually. Of course it is more difficult with the ZS35 than with the ZS50.
The Jtat adapter is only for the SD10. The SD15 and SD15 have a different shape of the mount. The JTAT adapter does not fit on them.
Since the SD15 is now in the shelves, i would hesitate to invest in any kind of construction work on your body. Simply buy a used SD14 and an cheap 25 USD M42 adapter and make photos
The SD15 is easier to operate than the SD14. I had not yet the time to investigate further into image quality. Noise levele seems to be better with the SD15 maybe one stop. But for any serious judgement, I need to make more photos with it and need time for the SD15 and SPP 4,1,1 learning curve
Best wishes