I have Southoast Linears loaded which, in this case, is GCEA. I think the low G works very well with this instrument and captures its tonal characteristics very well. This is a great instrument, unplugged or plugged. I love it.
By the way, I believe that you have a CE-3 which Ko'olau only made in limited production. The three speed knobs (volume, bass, treble) is the telltale sign. The CE-2 has volume and tone, and the CE-1 has volume only. Also the CE-1 has a rosewood bridge/fretboard/headplate configuration while the CE-2 and CE-3 have Ebony. The tone woods for the CE-2 and 3 models are also a higher grade.
John Kitakis at Ko'olau would be able to confirm all of this.
Mike