Should probably clarify it's an NA MX5, I'll be fitting a set of GGP and booking in with you for a setup when funds allow.
I've been using 185/60 14" Falken ZE912 for a couple of years have found them pretty average in terms of grip, not too bad in the wet, quite high wear. Difficult to be overly harsh on them due to my knackered dampers and less than optimal geo!
The 15" wheels I intend to fit currently have a mixture of Chinese brands (difference of 1.7kg between the lightest and heaviest!) so it's a blank canvas.
On my last RWD (MG F) I had GSD2 which were fantastic but no doubt they've been surpassed years ago!