If you are drowning in proposals, here are some criteria
High sounds lift us up, low sounds anchor us to the earth.
Zithers whose chords have 7 strings
(therefore high and low) are more "complete".
There is then the choice between the 7/7 zithereither 7 chords of 7 strings (or the 6/7, which can be found new at Thomann for example... or used but they are often without modulators);
or the 12/7 psaltery (12 chords of 7 strings).This instrument is heavy (8 kg)and takes up some space (80 cm wide)
Some people prefer 12/4 -12 chords of 4 strings, therefore without the treble. This psaltery is lighter and a little less bulky. Perhaps more austere. But no less beautiful.