Just intonation composition techniques?

Hi group,

I am trying to compose SATB choir music in just intonation. I am somewhat stuck or confused. I don't know if it relates to just intonation or composing for a choir, or just my general composition skills. I don't have any formal training in any of these subjects. My problem is:

My music tends to become very slow. And the vocal lines very simple, especially the bass&tenor part. I am afraid this will bore singers and listeners. But if I try to compose faster music, and make vocal lines move more independent, I find the result sounding messy even if it's still harmonious.

Here is a piece I'm working on right now:

http://tinyurl.com/clhob

or equivalently:

http://magnus.smartelectronix.com/examples/Magnus%20Jonsson%20-%20Walking%20to%20Class%202.mp3

It is a prototype recording, so please be forgiving on my singing and the audio quality. And be forgiving on my amateur lyrics. Once I write something that is good enough I'm hoping to get one of the university choirs to sing my piece.

I guess what I am asking is if there are any particular techniques that other just intonation composers use, that could be of general help for me. I've tried to google for information about just intonation composition, and there's not a lot out there beyond the basics of ratios, and endless tuning talk.

Any advice?

- Magnus Jonsson