Can you get Parada Spec 2's in 205/50x15?
Unfortunately Neil, with even fairly low powered family saloons running at least 16" wheels and usually at least 205 width, the OE spec Sierra tyre is fast becoming considered no longer a high performance tyre.

I had slightly different criteria to you as I mostly use mine in the dry and am prepared to back off in the wet when I use it then as the tyres I use are not as good as F1s in the wet ( literally none of the readily available tyres are as good as F1s in the wet )
You might find that you can get the fairly new Goodyear Hydragrip in 205/50x15 ( it is a sort of F1-lite type tyre more intended for family saloon use - Extremely good in the wet but average in the dry ) .

The F1 is an excellent wet tyre but although consistent in it's behaviour there are plenty of tyres that will grip more and be ultimately faster in totally dry conditions.

Unfortunately it's been some years since anyone did a tyre test on a Sapphire Cosworth on std wheels ( think it was Performance Car with a 4x4 version ) but I can scan some more recent high-performance tyre tests if you're interested?