first off my stock dunlops are 195/50/16 so i don't understand why you said that 45 series would keep it true to stock specs
i definately wouldn't recommend staying with 195s... 205 will give you more rubber contacting the road... if you want to corner wider tires will help you stick more as well as give you better traction during acceleration... and i also wouldn't recommend dropping down to a 45 series on a 16" rim because it changes the diameter of the wheel from stock... changing width gives more traction (and possibly decreased gas mileage, but minimal if tires are kept properly inflated) while changing diameter of the tire itself throws off your speedo and odo... i think it's around 5% difference from stock (so about 5 MPH for every 100, so not too drastic)... my recommendation would be a 205/50/16 but i think that you could get away with using any of the other setups recommended if so desired... no way u could toss a 220 on stock 16s though, no way... 220s would require a wider wheel than stock and you would also have to roll your fenders