If your just looking for strait Mobil 1, no frills or extended oil change intervals, then just buy Mobil 1 - 5w30. If it says anything else on the bottle, then it isn't the regular Mobil 1. Also, regular Mobil 1 is FULL Synthetic and uses "supersyn" formula.
Now, if you're looking for longer oil change intervals, as in you would prefer to not have to change your oil as often. Then, buy Mobil 1 Extended Performance. Mobil 1 claims you can go up to 15,000 miles between oil changes. I wouldn't go that long, but Mobil claims you can... you decide.
Anything that Says MOBIL 1 is a FULL SYNTHETIC regardless of whether it's EP or SUV or whatever. If it has the "1" on it, then it is Full Synthetic.
And as for the "supersyn"... I believe that is the fancy lingo that Mobil 1 uses to describe their Mobil 1 products. I believe every Mobil 1 product will say it has supersyn in it on the back of the bottle. Someone feel free to set me straight if I messing this up.