Finally I decided to use mygene, and it worked really well. Thank you very much!!
I'm thinking of using data from COSMIC database too. I would love to use myvariant.info too for this, but it seems it is still developing, so I guess I will have to use the Ensembl API.
(I guess you are one of the involved in the development of mygene and myvariant, as I found you in Github :P, so... congratulations and good luck! :) )