Wheel spacers or not ?

[Bozz]

I everyone, I had a full set of eibach pro springs fitted a little while ago and very pleased with them, My car has got 17" Classic classix at the minute but I'm tempted to go for some 18s but would it make the ride a bit hard ? Or would just having a full set of wheel spacers fitted make the 17s look better? All info will be appreciated