I’m with the pps that [name]Sierra[/name] and [name]Ciara[/name] are different names. According to Behind the Name:
Usage: English (Modern)
Pronounced: see-ER-? [key]
Means “mountain range” in Spanish, referring specifically to a mountain range with jagged peaks.
Pronounced: [name]KEER[/name]-a, KEE-ar-a [key]
Feminine form of [name]CIAR[/name]. [name]Saint[/name] [name]Ciara[/name] was an Irish nun who established a monastery at Kilkeary in the 7th century.
So, I’m assuming you like the “see-ER-ah” pronunciation, so I would go with [name]Sierra[/name]. As for [name]Bridget[/name] (a favorite of mine), I think the traditional spelling, [name]Bridget[/name], would be my favorite. I guess I pronounce the other spellings differently ([name]Bridgette[/name] looks like [name]BRIDGE[/name]-ette, and [name]Brigitte[/name] would be bri-jheet or bri-jhee-tuh) and [name]Bridget[/name] just looks the most classic to me.