I used to like alternate spellings, but now it really just seems to be the 'bogan' thing to do. Horrible generalisation, especially when there is a cultural reason behind it, but that's what so many people associate it with now.
Unfortunately I have to agree with the above.

At the end of the day, even those of us with the simplest names end up having to spell it for someone! Though for me personally I feel that alternative or "kreeaytive" spelling is try hardish, pointless and lame. But that's just me, who really cares what I think? LOL So whatever you like

My faves from your list are Sofia & Oliver. I'm pretty that spelling and also Sophia are both common, not sure how else one would spell Oliver though?