18" rims
 

I would like to buy 18" rims for my Boxster 2.7Liter.
Saw some great rims on the Internet, but the problem is that i realy don`t have a clou about rim sizes.
What should i buy ??
Front and rear ?
I realy like the RH cup ZW1, but i can only find them in 9x18" ET52 and 8x18" ET40.
( i`m from Switzerland by the way )
I also like the MAK Rennen .
Available in 8X18", 9X18" and 11X18"

Can someone please tell me if these sizes work for me ?

gr,Henk