Upgrading to xt3 or switch to z6

I've been shooting with a xt20 for the last 18 months or so after upgrading from an xe2. I have primarily shot with the 23 f2, 35 f1.4, 16-50 kit or 55-200. I have never loved the ergo of the xt20. It also has 2 primary issues that make me want to upgrade. First is weather sealing. I will leave the camera home sometimes because of beach sand or inclement weather. Second is stabilization. The 16-50 is adequate for stabilization, but it is quite slow. The primes, where I would love to shoot low light stabilised scenes don't have it.

So, I have been thinking about switching to the xt3, but it doesn't solve the stabilization issue for primes, and there is no standard zoom with VR and weather sealing. So I have been considering the xh1, but the lens issue is still there's unless I want to for over for the brick. I believe the xt3 is a significant upgrade over the xh1 but I am not really sure how much would affect me. I am primarily a afs shooter and don't shoot much video. How much better is the bsi sensor in the xt3 for low light than my xt20/xh1. I could see being happy with the brick and xh1. That would cost me around $2200 us right now.

If I went with the xt3, I would probably pick up the 18-135, which would give me reach, ws, and VR, but I believe the lens is significantly inferior to the brick. That would be around $2300.

Then comes the Nikon z6. I could get the 24-70 f4 which is by all accounts a very good lens, replace my 35 f1.4 with the 50 1.8, and have weather sealing and Ibis. I lose a stop to the brick, but gain significant high iso improvement over the xh1. I lose Fuji jpg colors, but I already develop from raw most of the time anyway. I shoot almost no telephoto, so that's not really a huge lack for me with Nikon right now. I will also pick up a wide angle manual prime for either system, the Rokinon 12 for Fuji or the irix 15mm for Nikon. Next lens would be a portrait prime, the 56 f1.2 for Fuji or 85 F1.8 for Nikon. I can always pick up a cheap 70-300 for Nikon. If I got the z6 I would get the adapter bundle.

Final decision is between the xh1, brick, 35 1.4, 56 1.2, Rokinon 12 for $3900

Xt3, 18-135, 35,56,12 for right at $4000

Z6, 24-70, 15,50,85 for 4300.

That's a large chunk of change for any of the three and I'm sure I would be happy with any, but I am feeling the brick or Nikon 24-70 would be better suited to daily walk around for me, and the Nikon is significantly lighter and smaller than the xh1/brick combo. I would love to hear your thoughts.