While I agree that Lost Horizon would be awesome at ProgPower, probably one of the bands I'd most like to see there, I think Manowar is an odd band to compare them to. They have a great deal more subtleties and intricacies to their overall sound than Manowar. I think Hammerfall has fairly well established themselves as the logical heir to the Manowar throne, and they fit the bill better, though I personally would listen to Manowar any day rather than Hammerfall.
But yeah, Lost Horizon are fucking amazing.
Ryan