For the 'looks', you really need to first decide on the exact tyre and then study the detailed spec.

Same tyre size such as 215/40/17 doesn’t mean the actual installed dimension among all tyre manufactures/models are the same.
You will see significant difference in appearance depending on the tyre make/model.

Also not sure you are aware of this but there is tiny offset between the R & L wing position against the centre line of the chassis.
You may not notice it with the OEM wheels but once you go for the aftermarket ones, you will see one side sticking out further than the other side.
So be aware if you are aiming for the 'hellaflush' looks.

Regarding the spacer, as long as it's from the well-known brand such as H&R, should be fine.
You may need longer wheel stud bolt.

Personally, for the offset, I won’t go anything beyond 40.
Otherwise, depending on how you setup the car, you will experience noticeable instability under hard braking, etc


Kaz