This is the best way to spell this name. As this is my name, I'm so grateful that my mother, worn out after my natural birth [painful labor], "accidentally" spelled my name this way! With just a 'c' or a 'k', ie "Eric-a" or "Erik-a", it sounds plain and barely emasculates "Eric", whereas "Eric-ka" is almost like "Eureka!"
I was named after Susan Lucci's character off of "All My Children": Erica Kane. And I think putting both a 'c' *and* a 'k' in the name loads it with too many letters.