we are identical twins (we think... we don't actually know)
Really? That's pretty cool. Maybe someday there'll be a set of identical quadruplets who decide to do Four Swords! ^_~
And... you don't know? Wow, that's the first time I've heard of twins not knowing. I guess family resemblance really can be strong at times, and it might not be worth the bother to do DNA testing or something(?)
By the way, it seems you aren't going to be the only ones doing a Link/Dark Link pair... I hadn't planned this, but my friend Melchizedek heard I was going as TP Link and called me up asking if he could cosplay Dark Link with me. He's commissioning a more general Dark Link based on an existing TP Link pattern, but he might wear black face paint and red contacts.
So, in short, we'll be doing just it a little differently from you two. Plus we aren't identical.
...Or female, which some might consider a stroke against us.
I wanted to do the twilight princess Link, but being my first cosplay (and pretty much first time sewing) I decided to phase it down a bit. Its now like a hybrid between Oot and TP... so yea
Heh, no kidding. I've been cosplaying for eight years and only now do I feel up to attempting TP Link (though admittedly I wasn't the one sewing for most of those eight years). I'm commissioning out the costume, but it's pretty spendy.
And I'm not exaggerating when I say this: for your first time costuming/sewing, your costumes are downright excellent.
As for variations on TP Link, your costumes remind me of this pair:
http://www.blogsmithmedia.com/www.dsfanboy.com/media/2008/03/a1942853_link_cosplayers.jpg...Costumes based on TP Link, but they've added decorated trim to the hats and tunics, and ditched the chain mail and some other TP-specific details. Also, even they're not identical, having blue tunic Link and red tunic Link together in one place is like they've got some clone action going on there. It's kinda like "Twilight Princess: Four Swords"... :3