[PHJim]

Rustyaxe - Greek bouzoukis are often equiped with D'Armond pickups; in fact this is almost standard for professional players.
Mando-things come in various scale lengths, numbers of strings and tunings.
Octave mandolins are about 20" scale and often have unison courses tuned GDAE or GDAD, but sometimes have octave tuning on the 3rd and 4th courses.
Irish bouzoukis usually have a longer scale lengthand more often have the octave courses. Citterns (not real traditional citterns,but thse used in Irish music) often have more than four courses.
There is a lot of confusion in the Mando world because not everyone uses these terms the same way. Quite often two players with essentially the same instrument might call it by two different names. An octave mandolin is sometimes called an octave mandola, although it's not tuned an octave away from a mandola(CGDA). Donnal Lunny called his mando-thing a "blarge". I've heard them called "Octophones". A guitar player I play with calls them all "Monster mandolins".
Master Toronto luthier Grit Laskin calls his "long necked mandolins" whether they have four courses, five courses, octave courses or unison courses.

Hope this clears things up.

Guitar players are not nearly as confusing. It's still a guitar whether it's shaped like a flying V, a dreadnought, a parour size; whether it's solid body electric, semi hollow electric, acoustic electric or acoustic; whether it has four, five, six, seven, nine or twelve strings.