Stay with the tire size on the car. There are no benefits moving to a different tire as far as speed or traction goes, especially if you are driving in a sometimes wet or snowy climate. The type of tire you are looking for would probably be a Grand-Touring Tire. You need one which has a speed rating of S or better. That leaves you: S (112mph), T (118mph), U (124mph), H (130mph), & V (149mph). Once you get past these, you are into the Z-rated tires, which are ultra-high performance. You could put these on your car, but you'll pay a premium for them. Realistically, you'll probably be looking at the T, U, & H values, and maybe V if the price point is good.
If you want a longer running tire (more mileage), you need to look at the UTQG rating on the tire. On Tirerack.com, they explain the UTQG as:
The U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration's (NHTSA) Uniform Tire Quality Grade Standards (UTQG) were originated to provide consumers with useful information to help them purchase tires based on their relative treadwear, traction and temperature capabilities.
NOTE: While you don't live in the US, the UTQG is still a great way to identify which tires may/may not work for you.
What this means is that the higher the UTQG, the longer lasting the tire should be. Be careful, though. The number only relates to other tires produced by a manufacturer (such as Uniroyal, BFGoodrich, etc.) and do not relate across brands. (ie: A 600 from Uniroyal does not equate to a 600 from Hankook.)
The second part of the UTQG are two letters which indicate Temperature and Treadwear. In your case, you should be looking for Temperature of A and Traction of A or AA. These values are less subjective than the number portion of the UTQG. They are specifically as follows:
Traction
Grades Asphalt g-Force Concrete g-Force
AA Above 0.54 0.41
A Above 0.47 0.35
B Above 0.38 0.26
C Less Than 0.38 0.26
Temperature
Grades Speeds in mph
A Over 115
B Between 100 to 115
C Between 85 to 100
Whether I buy my tires online or at a store, I always do the research on them, to include how people review them. You'll always get people who say they hate a specific tire, but look to see exactly what they are saying and use it wisely. You can always purchase the tires you like online (in most civilized places, that is) and take them to a tire shop to have them mounted/balanced. Many online tire stores even have road hazard warranties available at a reasonable price. Personally, I don't leave home without them ... I've been burnt by the pothole way too many times.
Ultimately it will be up to you to choose a tire which suits you. Hopefully this will get you on your way.
