Came here to essentially say what @Ghost said.
If you go with Shimano and not Sram then you won’t need a new hub.
XT shifter is a bit nicer than the SLX, but unless you can get the XT for minimally more than the SLX it’s not worth the added expense.
I have Sunrace 10sp 11-40T cassettes on two bikes and I wouldn’t hesitate to buy another if I had the need for one.
An elliptical narrow-wide chain ring is nice too. It makes a subtle difference, but it is noticeable.