Seems you're on the right of the stage (as you look at it)in the front row of the tiered seating, just beyond the area that is set aside for standing fans at some concerts (although this is an all seater event). In most arenas, however, there's a separate area for wheelchairs, so you might want to give a ring (you say your husband's disabled, I don't want to make assumptions.)
On a more definite note - saw that show last year in Dublin, you are in for one hell of a night. It is TERRIFIC! The band and orchestra are great, and the effects are fab. The narration is done by Richard Burton's giant talking head - just wait and see...! And of course Justin Hayward reprises his role in this. I'd love to see it again. I'm so jealous.