I used to love to make long lists of various spellings for any given name, but now I am a mom and don't have time for that. lol

You could replace the S with a Z as suggested
change the first a with almost any vowel (though it can change the sound of the name)

I guess you could also double the B or Z/S
Isabbela (that looks way off to me, more so than the others lol)

As to MykkenZ having to spell her name over and over, well, mine is Rachel, R-A-C-H-E-L, and well, I ALWAYS have to spell it for people. Always, so if my name is uber common and old, and I have to spell it, yeah, not a big deal to have to spell it.