360 Event Hall Projection

Hi there,
we have a 360° event hall projection and would like to use unreal for rendering.
how can we render out “panoramic” images/movies so that they do not have camera angle distort and connect again. we have 4 walls and try to use 4 camers (at 90° angles, however the distortion at the corners are clearly visible. we tried 360 render, but we need a resolution of around 12’000x1000 wich is the projection of all 4 walls.

any ideas?

many thanks