shower mosaic tile grout

Searching for best grout solution ?

I have installed a wedi shower pan with mosaic tile over thin set. What is the best approach to grouting : urethane, cementious, or epoxy.

I like the sounds of urethane, but became concerned when I saw that it was limited from re-grouting? I assume at some point some amount of regrouting would be involved, so does that rule urethane out ?

thx

 

You likely have this done already but I found this , thought you might be interested in reading the posts over there.
http://www.johnbridge.com/vbulletin/showthread.php?t=48551&page=3