Guitarists, please advise!

Hello. Was told to comment here. I've played guitar since 1987 and have never heard of a soprano / alto / 11 string guitar. Doesn't mean they don't exist, but they'd be pretty niche if the do. Like the baliset: https://www.youtube.com/watch?v=dDwFgSAOBLA which doesn't exist but is based on a Chapman Stick: http://www.stick.com/

*now, guitars and tunings*
There's the guitarra baiana which is a Brazilian 5-string guitar: http://en.wikipedia.org/wiki/Guitarra_baiana
And you have your basic 6 string guitar. With a variety of tunings: http://en.wikipedia.org/wiki/List_of_guitar_tunings There's a 12 string guitar that also has the same tunings with octaves differing the strings
There is such a thing as a 7-string guitar, which has these tunings: http://en.wikipedia.org/wiki/Seven_string_guitar
And an 8-string guitar: http://en.wikipedia.org/wiki/Eight-string_guitar
There's also a 9 and 10 string guitar, a lap steel and a pedal steel guitars. All of these have tunings available on wikipedia.

Bass guitars also have a range of strings and tunings:
http://www.studybass.com/gear/bass-tuning/bass-guitar-tunings/
http://www.12stringbass.net/master.htm?http://www.12stringbass.net/tuni…

I hope that's of some help.

I was involved in the Sibelius G7 group, and one of the big issues that emerged was that guitarists seem to have very varied mind sets about their instruments.

When I said that I would like support for the capo, which to me makes the guitar act like a transposing instrument, everyone pitched in with different views about what a capo meant.

For songs, for example, I might want the vocal line in D but the guitar in C: capo 2. Other people didn't see it like that at all. We never agreed on what you would show on the tab. I don't read tab, so I didn't care!

Then there is the problem of fancy partial or changeable capos, like the spider capo. Or bridges that can change tuning at whim part way through a tune. The Line 6 Variax guitars and similar Roland/Fender guitars can also switch tuning anytime.

I don't have a solution to this nightmare. It almost has to be user configurable.

Aren't the expressions "Soprano, Alto, Tenor, Bariton, Bass" originally meant for the register of vocal ranges? Meant specially for the vocal ranges in a choir? Since ever, most choirs consists of amateur singers and their members are singing comfortably in their native limited range. Barnabas sings the bass voice, because he has a natural deep voice, Bartholomew sings the bariton voice because he can sing there without stressing his voice, Elizabeth sings the soprano because it's very near of her natural speaking voice, etc.
Some musical instruments can produce a wider tonal range than a choral register voice. That's why it isn't logic to name them with a register name like soprano, etc. That's why A cello isn't a "bariton-violin" and a "bratsche" isn't a soprano-cello. They produce nice tones over more than 3 or 4 octaves (or even more?).
But not all instrument builders respect that rule. Maybe, they tried to recommend their construction for a certain tonal range. As example Adolphe Sax who invented the saxophone for tonal register ranges in marching bands (Alto, Tenor). But after, some musicians didn't care about such recommandations. They use them in wider tonal ranges (Dixie, Jazz, Pop). But the instrument has still it's historical and well established name - a good reason to continue to use such names.
A guitar - or their predecessor, the lute, was never a "register-instrument" in a choir, in a traditional orchestra or in a marching band. Because it was never loud enough. A lute's range is always more than 3 octaves, a guitars range always more than 4 octaves. Why give them a name of a limited register range?
Maybe, some instrument-builders saw a reason in a limited number of strings or a shortened fretboard. Maybe, that's why they call a Plectrum-Banjo a Tenor-Banjo and a 4-String-Guitar a Tenor-Guitar. But their tonal ranges are still above their tonal register range.
I'm sure, the main reason was to give them a musically sounding name that distinguished them from the mainstream instrument of it's kind. If it was above the already known instruments, they called it "Alto- or Tenor-", if it was below, they called it "Bass-".
In my opinion, specially for guitars a wrong kind of giving names. Is somebody calling a small drum a tenor-tom, just because the deepest drum calls bass drum? The floor-tom could be the bariton-tom?
For Instruments, constructed after the 19th century, the use of register names doesn't make a lot of sense. Because of their tonal range, because of the possibility of amplifing them and because of the purpose of it (no register instruments).
My recommandation for guitar notation is:
Always declare the tuning of the strings.
For playing and notating a guitar, the name of the guitar doesn't matter as much as the tuning of it. If a guitarist has to bend the strings a lot, he drops the tuning down. If he plays a lot with a slide, he prefers another tuning. And sometimes, picking style prefers also another tuning.
If one cannot buy historical gut-strings for a historical instrument, he will low down the tuning for not destroying the instrument. Maybe for something like this: http://de.wikipedia.org/wiki/Schrammelgitarre. No way to notate such instruments by their "unknown" name. You need to declare how you personally tuned them.
There are so much different guitars, banjos, lutes, mandolins, etc, with so much different (marketing-)names. But as soon as they have the same tuning, you can play and notate them in a similar way.
That's why it is very important to declare the tuning - and after that, maybe the fingering on the fretboard.
I hope, my thoughts will help for a decision :-)