Either of these oils will work nicely.
Mobil 1 Extended Performance will likely provide a little bit better protection and will take a much longer time to "wear out" than M1.
How long is your trip to school, work or wherever you usually drive to?
If your answer is under 10 miles or 20 minutes, you probably want to do oil changes no less often than once per 5,000 miles, and you could save money by not buying the EP.
How long do you wish to go between oil changes in miles?
If your answer is 7500 miles or less, you could save money with the EP.
Then again, you could decide to just get the EP since it *is* a better oil and only costs a little more than the standard M1.