Which Tyres for C220 CDI 2011 model?

[legendracer]

The car runs around south east England motorways mostly. I'm considering Michelin primacy 4 over cross climate 2. I think primacy 4 can deal with the often wet roads and snow days are only for few weeks which is a compromise to be made.

What size should I use? Now it's on staggered setup. 245 rear and 225 front 17 inch wheels which I assume to be stock sizes. Can I get slightly wider tyres? Any insurance or MOT problems?

What sidewall size should be considered. Any latest deals links please.
Thank you.