Render realtime panorama (cylindrical equivalent, not spherical)

I'm trying to get a texture out of Unity and into Spout ( http://spout.zeal.co/ ) that is the equivalent of a 360-degree camera with a 'normal' vertical FOV (like 35mm equiv). To clarify, this texture would be the equivalent of a cylindrical panorama (rather than spherical), and this is with the goal of bringing this texture into TouchDesigner in the end.

I've tried making multi-camera rigs a la https://www.assetstore.unity3d.com/en/#!/content/25091 but there is a degree of lens distortion per single-camera FOV that makes some unacceptable distortion no matter how many cameras are in the rig.

I had some interesting suggestions from friends regarding rendering reflections from a cylindrical object but I understand there are some major performance limitations with that approach.

I'm considering rendering a cube map in Unity, trying to send that through Spout, and then doing my pano camera stuff on the TouchDesigner side ...

Any thoughts on how to best approach this?

Thanks,

N