If I am understanding your statement correctly, you already HAVE sliding door hardware for the opening and are looking for alternatives?

Assuming that is correct, you could go with a roll-up door. We have some available on our website: http://www.postframeaccessories.com/roll-up.html. These are like the types of doors you typically see on storage units where the door rolls up in a coil above the opening.

Feel free to contact us with any questions, we'd be glad to help!