I'm not sure what's available "across the pond", but I'd have to believe Pirelli tires are. Their Scorpion Zero Asimmetrico tires come in 255/55/17 and although they're "truck" tires they're for street use and have a load and speed rating that's more than adequate. They look as though they would appear (and perform) just fine.
Bridgestone Dueler H/L 400 tires are also available in that size, are classed as highway all-season tires, and have adequate load and speed ratings. I don't know if these are marketed outside the U.S., though.
What model year is your Turbo R? Are you using the original wheels or did you change them out?