I just used a pair of drawer slides per door.
They work pretty well so long as you have thick plywood for the doors. I first used 1/2" and it was not straight enough and when the doors met up it looked pretty ghetto. 3/4" worked well for me and the pics in the thread should show how I made the top lip of the doors. Again more ghetto action but it got hidden with the tiles so you'll need to take a bit more care!
Build's lookin' good =)