I really love this question for some reason. If your intent to become an Angel after death is your desire you can. Remember, no one is any greater or any less than anyone else on Earth or in “Heaven” because we are all One. 

There are no big I’s and little u’s. Your only limitation is what you yourself can create. Once you transcend you will quickly realize that the spiritual realm operates a little differently than I think you understand at the moment, but yes you indeed can be an Angel if you so choose.

The concept of Angels is largely based in Religious thought but like anything else everything first begins with thought. So your idea of what an Angel is  can be assumed by you with nice wings and a flowing robe if you so desire. In nonphysical reality thoughts are actualized and made known instantaneously without judgment or prejudice.