2beers,
My prescription RayBans occasionally reflect in the Alpha visor, but it's one of those things to get used to. Most of the time I'm looking/focussing well outside the cockpit, and the reflection is not an issue: only when I glance in the cockpit does the reflection come into focal range and become noticeable.
Re the ear seal concern, David Clark have a product called Stop-Gap, which fit on the spectacle arms and seal the gap in the headset. Aviall stock them, and any David Clark outlet should get them for you.