EB2 is applicable. The best is to start the processing of GC once you join  the company with OPT card. With that, ur company's financial ability to pay you will be reflected thru ur paycheck and if the prevailing wage is larger, the company's ability to pay you after getting GC will be reflected from company's tex return docs. The wage that the company pays you at current does not necessarily be the equal or greater than the prevailing wage. Only for position advertised for GC, the payment shoulde me equal to or more than prevailing wage. 

While the GC processing is going on, you can apply for H1 (during normal H1 application season), since the total processing time is over 1 year from the time u start the process and ur OPT will be for 1 yr only.