Not many folk have tried all the wheel options & give incorrect advice.
I've tried everything from 13x5" Cinq Abarth Speedlines, OEM Cinq 13x5.5", 14x6 aftermarket, Sei Abarth with OEM 14x5.5", & Cinq + Sei on 15x6" wheels with all sizes of tyres 175/50/13, 165/55/13, 175/50/14, 185/50/14, 195/45/14 & 165/50/15 & overall the best combination in terms of feel, feedback & grip are the 165/50/15 on a 15x6" wheel.
Though you can only buy very few aftermarket 15" wheels in a 6" width as most are at least 7" wide which is a no go on Centos.
By sticking to 6" wide & a 165/50/15 tyre you can go as low as you can on 175/50/14 shod car & in fact get more clearance than you do on a 185/50/14 or 195/45/14 shod car.
And our track day Cinq runs height adjustable AVO front coil-overs on 300lb springs & helper springs to prevent the spring unseating on droop, Eibachrear lowered springs with a coil cut off to get it lower than it originally sat plus we run the longer 6 speed gearbox & get no issues whereas on the Abarth 14" wheels on 185/50/14 tyres the off-side tyre rubbed badly on gearbox & gave a very soggy turn in.