Suggestion - do not take the GMAT again unless you are sure you will get 750+. I see people have GMAT lower in second time and feel it's silly to explain why with a 700+ score he still want to take it again.
Spend time on ESSAY, that's the most difficult and important part.
As for recommendation letters, try to mingle w/ people around you and let them know you well. Given that you are really good at what you are doing, your boss (or his/her boss) should recognize that and write very good recommendation (better something really personal) for you.