I thought I'd provide a little insight as to what the girl above is doing with the kalimba and guitar composition. The kalimba Yasmin is using is a Meinl KA7, specifically made for E tuning. This bodes well for mating with a guitar, since E is a favored key for guitar. Yasmin is using the kalimba to arpeggio chords, while striking a chord and note melody rooted in E on guitar.
So, ukulele is tuned in C6, and the majority of kalimbas are tuned in C. Ideas?
Your question got me thinking, and now I plan on installing a passive piezo disc in a kalimba sometime this week. The reason being, I can then plug it into my looper pedal, and overdub complex kalimba melodies on the fly.