I wrote to trek and they said:
"This frame is not disc brake compatible, the fork
can accept IS disc brakes. "
I looked at my frame and the same two holes that are found on my fork are also on my frame in the rear.
The hubs are shimano m40 i believe, i still dont know if the hubs are compatible though.
If it is to much work and money im not doing, v brakes will be the thing. If everything is compatible i will change.