Bi-folding Closet Door Kits include track, and simple wood knob. Alternative dummy handle options can be found here.
Allow an additional 1-3/4" in finished opening height for track and necessary gap allowances. (A 79"H Bi-fold door is for an 80-3/4"H opening, and a 77"H Bi-fold door is for an 78-3/4"H opening.)