There are 2 kits. The Brembo kit & the '695 kit'. The '695 kit' wasn't available for the A500c but this could have changed.
If you are not interested in the Matt black 695 wheels then the 695 kit isn't for you. TMC are selling it for a 'resonable' £3.6K but do you have someone to fit it and in particular the ECU upgrade ? One time the SS kit came with a 'spare ECU' (this has changed) - I would suspect that it would need an Abarth technician to do the 'mapping' of the existing ECU for the upgrade. Aside from all that the '695 kit' does not give you the real mccoy with the Garrett turbo upgrade as you have on the Grand Punto SS so it is a bit of 'Pretend kit'.
If you decide to lower the A500c with lower springs, ideally it's best to fit better shocks. AVO did a very resonable prices set of rear shocks that would work with the Eibachs but there were some issues with rattling. This may have been fixed.
Paying the money for the Koni suspension kit with the FSDs and the Brembo springs sounds like the best option (check if the Konis can be replaced 'locally' if they go wrong). Not too sure how much they would be 'dropped' over the standard setup. These Brembo springs
may possibly work better than the essseesse springs. I was always led to believe that the esseesse springs were the same as the Eibachs.
Upgrading to 17 inch wheels will still be heavier than the 16s you currently have unless one opts for OZ Alleggerita. (Click
here).
I have the Brembos on a MiTo 155TB and they are brillant but they are needed on a heavier car. A A500 with 140bhp or 160bhp IMHO doesn't need them plus it adds weight. You could just go for a better set of pads.
Lastly, the Pro Race wheels come in a 38 or 30 offset. 38 is the wrong size. 35 is standard. 30 are fine and work with Brembos if you decide to fit them at a later stage. Only some 35s fit with the Brembos but spacers could be fitted. They can be got in Graphite, Silver, Black & white. Graphite colour sounds tempting.