As you have so much time and your employer is interested, i would suggest go for it.
yes you can apply for GC while you are in EB2. Most of the people prefer to do H1b and then GC just to be in safe side.
One thing which you have to remember is your F1(OPT) is non immigrant VISA and GC however is immigrant VISA. That means if you ever have to go back to Nepal before you GC got approved and if your current F1 visa is already over and have to renew it then there will be problem and you will be denied for sure because you already violating the non immigration visa's intention. H1b however is dual intent visa (immigrant and non immigrant visa). That's why people prefer to apply GC after H1b and they don't have any problem while stamping just because they applied GC.
Hope my answer help you.