There is no official first name for Palpatine, and I think it is better for the mistery of the character to remain unknown, just like his past. I really think the Darth Plagueis novel was a huge mistake by Lucasbooks and I am glad it is cancelled now. Cos Dash_t was a character from the first drafts that resemble Palpatine in some aspects and Frank Palpatine comes from a line in TPM taken too literally.
PALPATINE : ...the Republic is not what it once was. The Senate is full of greedy, squabbling delegates who are only looking out for themselves and their home sytems. There is no interest in the common good...no civility, only politics...its disgusting. I must be frank, Your Majesty, there is little chance the Senate will act on the invasion.