I used a ZUM Radio board. From <a href="http://mmdvm.blogspot.com/" target="_blank">http://mmdvm.blogspot.com/</a> .. These guys are great. I ordered a kit board got my parts and bang, I had a DSTAR repeater!
Video of it in use:
<a href="https://youtu.be/NNHECrR5PYc" target="_blank">https://youtu.be/NNHECrR5PYc</a>
Check out www.badassradios.com