Most of what you are hearing doesn't mean anything. (these guys ride different areas and may or may not be same fitness) These are apples to oranges comparisons.

Best thing to do would have been to ride around with your geared bike on the course/road conditions you expect. Then experiment with what single gear works best on the gear bike.

Once you have determined that play around with the gear calculator and come up with the chainring/cog that is equivalent.