dude if you hit any Massive rock there is a good chance you will scrwe your tyre it wont matter what you have... also i would be checking you have not cracked you rim...
one other thing i dont understand why you must have all 4 same tyres ??? it's not going to make you uncool like anyone will even care or be able to see when you are driving past them at 80kms an hour
one last thing the tyres on them no would not be "nissan factory items" your would be 7 or 8 years old and would have been replaced a couple of times within this time. probably also at compliance so ring around a few shops and see if they have the same ones you have.