It's a hard choice when moving from one system to another...... so don't rush.
When I moved from Sony to Fuji I went all out (like I do) lol

and bought the following...
Fuji XT-2 + Booster Grip
35mm f2.0
56mm f1.2
90mm f2.0
10-24mm f4
16-55mm f2.8
50-140mm f2.8
1.4x TC
I didn't own it long and was lucky enough not to lose much if at all when selling it off.
I used it for one paid wedding shoot and although I could get by, it lacked the high DR/ISO I was used to.... I decided to move back to Sony.
Fuji is a great system and it saves some weight but for me I missed the FF aspect of Sony...... that being said, the cost difference between the systems is massive! It was one of the reasons I moved to Fuji, as it was a cheaper system overall.
You may find yourself in the same situation when you compare Sony to Nikon, the is probably the cheaper system.... so you need to ask yourself if your willing to make that leap and spend that big extra
My Sony GAS is low and high...... keep thinking I will get some more lenses and a body.....
I am loved the Fuji 90mm f2.0, so perhaps I will consider the 135mm f1.8 GM when it eventually comes out.
The 90mm f2.8 Macro would be nice too..... oh and the 100-400mm GM.... oh and the.....

lol