Read up on tirerack, treaddepot, discounttiredirect, or some other online tire company that provides reviews for tire manufacturers, models, UTQG rating, warranty, shipping, customer service, etc. Then chose one you're comfortable with. As for sizes, see below.
I've also ran Polk 3-way speakers in my old vehicle and then installed/transferred the same speakers into my Accord. Been running strong and still clear for almost 10 years now. I plan to go with Polk again, or at least listen to Alpine as Tim suggested ....