Help: Nikon Z7II low‑light prime lens recommendations for ISO‑heavy shooting?

ngl i’m working on club sessions where the light drops to 100 lux and still want that sweet shallow depth of field

• Nikon Z7II (45 MP FX) at ISO 6400, trying 2‑8‑second exposures
• want a prime that keeps noise under 25 %
• shots must be centered on a single spotlight, but background glow is a must‑have

currently I’ve got a Nikon NIKKOR Z 35 mm f/1.8 – it’s great on day but at 6400 it throws out a crazy halo on edges, and bokeh looks weird.

My options now:

1. f/1.2 50mm prime – expensive and only available in NIKKOR Z (does it work with the crop of Z7II?)
2. 24mm f/1.4 – more wide but still early morning work
3. a vintage f/1.8 35mm manual, the one i’ve seen in the thrift shop – lens has a 9‑step aperture dial, not exactly 1‑step.

Question: is the f/1.2 the way to go if I want noise control, or does the f/1.8 with an FX sensor push it out of range? also any third‑party brands (Sigma, Tamron, or a new L‑lens) that do this better?

would love the real world numbers, not a list of press releases. lol

thanks