#1 yes, just get the 4 lane.
This is a 4 lane system on the Midmo.
You see that smaller diameter tube back there next to the base? That is where the 4th lane sensor is mounted. Just to have them connected. You can then setup TM for only 3 lanes.
#2 You don't need a CD ROM. You can just download the program from the link he gives you or I can send you a link.