[anrakushi]

McDonald ＝ マクドナルド
this is perfectly acceptable, this is taking an english word and pronouncing it with japanese sounds. this is EXACTLY the same was that your name is put into katakana for Japanese to use.
The chinese do exactly the same thing, they take sounds from their language that are similar to make the name of McDonalds. 麦当劳 － maidanglao (i know how to say this but not how to try and explain the sounds in english)

anyway you are free to do as you wish but as i said you will be looked upon as strange in Japan. why would you want to use a japanese name in Cali anyway? have some pride in your own name, respect your parents choice of name.