advice for hardware - for bottom of sliding doors

We don't need replacement parts. Rather I am installing 3 30x78 doors on a bypass track. My wife wants me to install (i thinks it's overkill) a bottom track with rollers to take the load off the top joists.

i am trying to find out what parts are needed for the bottom track and hardware, what the cost is and if you also sell the top track and rollers. The total length is 106 inches.

thank you