Hi
I run Focus ST 170 wheels with 205/40/17 tyres. I also run 30 mm HR hubcentric spacers front and rear, you will need these spacers with the ST wheels, the bearings only load up the equivalent of 16mm spacers. Over the past six years there has been no problems with the wheel bearings. I have also fitted the equivalent of the FRP springs , a 35 mm drop. I have had no issues what so ever with this set up.
Focus ST wheels are genuine ford, they are reasonably cheap and they add a period look, if that's what you are after. Photos of the car are on my project thread. Project Outrageous, I did try to paste the photos but was not able to do so.
Regards
Richard