I wrote a fun little web app to draw snowflakes a few weeks ago: http://www.create-a-snowflake.com/ . I settled on 8 sides, although the first version had an option to have anywhere from 4 to 20 sides.
But the scientific reality is aesthetics too. Seeing how the snowflake is a textbook example of beauty found in nature, I would personally find myself obliged to represent the snowflake according to it, even for the purpose of your application.
I wrote a fun little web app to draw snowflakes a few weeks ago: http://www.create-a-snowflake.com/ . I settled on 8 sides, although the first version had an option to have anywhere from 4 to 20 sides.