"We're installing two 32" doors into a rough in 64" opening. This will allow for a 1" overlap. Easy"

As long as you are narrowing the rough opening 1 inch less than typical. For 32" doors with a 1 inch lap, your width would be 65"

82" is a "standard height" for most applications. We typically went 82-1/2" but you have to take into consideration the flooring used and adjust accordingly.

This is also assuming your jamb header and legs are 3/4" frame thickness. Some pre-hungs have thicker jambs.

64" rough opening would allow for the 2 32" doors with the 1" overlap as the 3/4" thick jambs on each side would bring the actual opening size down enough for the overlap. A finished opening of 64" would be too large.

Millworkman, Wouldn't that result in a 1-1/2 inch overlap?

The finished opening for bipass should be 63", which is why it's hard to convert to bifold in the future.
The height can be trimmed off the doors if you get it wrong but where I learned the rough opening was almost always 2" larger than the door size. 82 1/2" would be OK too as you may want room for carpet.
Bipass hardware is usually ACME or JOHNSON. Look them up online for specs and clearances.

They are asking about the HEIGHT not the width. I would like to know also, as it isnt clear once you measure the rough opening, to know the eventual door height, how much do you subtract for the track?

The amount you subtract depends on the specs provided by the manufacturer of the hardware.

Finished opening should be 63” wide for a 1” overlap using 2 x32” doors. That is the width with you jambs installed. This means your rough opening, where the studs are, should be 65” to allow room to adjust the jambs when installing. Jamb widths are typically 3/4” which would leave you 1/4” on each side to level the jambs. With respect to height typically, 2.5” more than the door height for rough opening but this will be dependent on the hardware you use. Trimming door height, if needed is not as deal breaker.