H&R, Eibach, IL Motorsport are good products and you don't stress the struds with them, because over 15mm they come with inkluded struds.
A Set of 30mm Eibach spacers weighs about 730g - rather underwhelming.
But again: who tells FCA/Abarth?
If you want a good looking 124Spider on OE wheels (9,8kg for the Abarth wheel), which choices do you have?
I can tell you, that many owners in Europe use spacers on their 124Spider and MX5 - and they are not dissatisfied.
This thread is about spacer on the 124spider, so let us stay to the topic.
There are enough threads about wheels.