Sounds like you have 6 foot ceilings?
Anyway, bifold closet doors may be an option as well.
-jasper

How about using flat hollow core door? Cut them down and apply molding strips to the surface with glue for the six-panel look.

You could special order, but $$$$$

Here's the crazy thing I did (but it turned out fine - not sure I' do it again, though):

Install prehung, flat hollow-core doors, and cut them down to the needed lengths, jambs and all. Ripped and cut a filler piece to fill the bottom door gap (due to the cut), and glued it in.

Note: after the cut, the hinges and door knobs were low and awkward-looking. I bored new lock holes, morticed, etc, and used the bored-out piece to fill in the old hole, finishing each hole with Minwax performance wood filler (two-part stuff). BTW, mixing batches on a piece of cardboard with a putty knife is far easier than using their plastic mixing lid.

After the doorknobs were adjusted, it looked fine (imho). The low hinges didn't seem to catch the eye.

And lastly, you could add molding to the door surface to get that six-panel look. Note that you probably can't do this for pocket doors, since it might be too wide for the pocket.

....this all being said, ordering custom six-panels might sound like an affordable alternative after all.