Stick with the stock widths, you'll hate the wider tires on stock rims as it will run the center out of it pretty quickly
Good advice. I've played with a lot of sizes on my Comstars and found that going for the fat rear look wasn't worth the cost of quicker center wear and diminished cornering as a result. Counter to what I thought, a sticky 90/90/19 front and 110/90 18 rear gave the best handling and traction, though the skinny front got a bit dwarfed by the fender.
The actual stock sizing from Honda calls for even narrower tires than the 100/90 most people(myself included) run up front. Rear is 4.00 metric? which is even narrower than the 110/90 19. Squeezing wider tires on changes the profile and you begin making choices of looks v.s. handling.
100/90front, 120/90 rear is a nice compromise and is what I run on my street bike.