This is just my 10p worth.
A 10x scope will be enough to get you hitting at 1000 yards.
I mostly shoot 1000 at about 20x with a S &B PM2..... plenty of mag , not too much re mirage, decent eyebox , ni e and light image.
Higher mag will cost you in £ , image will be dimmer and eye position more critical....obviously scopes will vary re glass quality and image brightness ...usually related to how your budget can stretch.
Hi mag is nice to have but I bet you shoot mostly with it backed off to between 20x and 30 x.