I never get past the 5th fret...
Here's something to consider if you go with a Gibson/Epi double-neck: there are only 20 frets. And, on the 6-string neck, it's really hard to get all the way up there.
Did a couple of gigs last year with a guy who has the Epi doubleneck (we did a Tom Petty tribute thingie, so a doublenecker was of course needed).
I'm quite sure he spent at least 20 minutes throughout the set tuning that thing. Just wouldn't stay in fucking tune for more than a song or two.
Not sure if that's a general thing with those guitars or if he just has a terrible one.
I wouldn't get one without trying it first for sure.
Take your standard SG neck wonkiness, double the tension.
I have to say that I love my Danelctro 12-string. When I looked for pictures of Dano double necks all I saw was one with a standard and baritone 6-string.But as far as "Spanish guitar" is concerned, I would probably go with the Dano. It's relatively lightweight compared to others and Dano has a great classic 12-string electric tone that competes with Rickenbacker.
you just joined a Led Zeppelin/Rush/Eagles/Mahavishnu Orchestra/Yes/Triumph - tribute band