I can only encourage you. I sold off my Nikon gear (D700 plus lenses) after getting the A7II to use with my CONTAX Zeiss lenses. After a short "probation", I completely got out of Nikon
I use the 2.8 / 28, the 1.7/50, my favourite 1.4/85 and the 2.8 / 200 I also own the Yashica 2.8/135, which I am just rediscovering and the 28-85 and 80-200 Zooms. All of the Zeiss lenses give me more pleasure in use than the Nikon lenses I had. Manual focus is easier than I anticipated. Notwithstanding that, I am still sitting on the fence regarding the Techart Pro adapter, which I love conceptiually as it picks up the idea of th CONTAX AX, which I also own.
To your question regarding adapters. I started out with a "cheap" Fotodiox adapter which works fine. I wound up buying the much more expensive Novoflex adapter, which just feels better. I just didn't make sense to me to ditch my Nikon gear and switch to Sony / Zeiss and then skimp on the adapter. The haptics of the Novoflex just fit much better to the ensembl than the cheaper products.
Sorry for the long winded response. I would be curious to hear about your experience with the 135 on the Sony. I am considering trading up from the Yashica to the Zeiss...