There's the opto endstops holders and flags I designed for my reprap wallace and optos from reprapwolrd, it's design from scratch with blender for M6 rods, except for the y-flag wich is a derivate of the z-flag from http://www.thingiverse.com/thing:8509.
Feel free to improve and tweak.

Print and see pictures on how I assemble it, I could at ths time only take pictures with my cellphone, I will try tomorrow to have better pics, with more light.