Sora because it sounds more unique imo.
Wait, why would I possibly end up in a situation where I can't even name my characters after random furniture?
I don't think this matters nearly as much as you think it does.
"We don't care what people say, we know the truth. Enough is enough with this horse s***. I am not a freak, I was born with my free gun. Don't tell me I'm less than my freedom."
Astro.. only because I watched Farscape recently (Stark - Astroboy:P)
Don't really like the other ones all too much.
I'm not exactly fond of any of them... but I'd go with reef. Sora seems like it would be overused, and bonk sounds like a dumb orc's name.
Honestly, if i were left free to choose, i'd choose not to pick any of them.
Would prolly go with Sora or Astro. Sora can fit any female character and Astro sounds pretty good imo.
That's just my opinion about how those names sound to me. And really, what's the big deal with the fact Sora is a common name in Japan? Jędrzej is a common name in Poland and I don't really feel like naming a character like that. All I asked for is why are those 4 chosen? Those are 4 names that don't have ANYTHING in common, except the fact they are short.
I would choose Astro, I like that dog from the Jetsons! But thats probably not what you were referring to.
GL naming your toon Sora. It's probably taken on every realm.
Bonk for the win!
Go with whatever you want to be called on voice chat. This is actually how i judge names.
People with fancy long names like honeyfuriouslol (random name never meet anyone with this name) will always just be known as just Hon or Honey so it's a great start that all your names are short. Personally Bonk sounds awesome but every time someone would say it or type it in chat you would sound like a moron, no offense "Hey! Bonk get out of the fire" Astro sounds like a bad cartoon hero or his sidekick, Reef makes me think of Beef jerky for some reason, so i would go with Sora if it's available, easy to say easy to remember and is short enough.
Bonk would be my choice, because some people think I'm bonkers, but I just think I'm free, man I'm just livin' my life, there's nothin' crazy about me.
Bonk.
(in other words I think it's the funniest and the others are rather boring).