long story short:
just bought myself a set of wheels that are 18x8 ET34 for my IS350
The rims are currently rubbing on my brakes (Front) and planning on buying spacers.

My question is, will 20mm all around be good enough without any rubbing?
Also my tires will be squared 225/40/18s and I am lowered 1" with springs (Swift)
Pls and thanks!

Also, if anyone can educate me on how to know what kind of spacers to buy and such.