on 17x7 you can go to a 205-50-17. pretty narrow but will give the best wet traction as far as sizing is concerned. if you have to have the widest tires possible go 225 45 17 and get
michelin pilot a/s w rated great all around traction but expensive.
dunlop sp5000's z rated excellent wet traction
dunlop sp9000's prolly second to the pilots mentioned above.

for ride quality michelin has it cornered. no one comes close.

http://www.ocaddict.com

thanks beefgg for the sig