Sorry I can't answer your question directly; I'm not familiar with Armytek headlamps.
I know that Zebralight has the H502r, and the H502pr still listed as available on their website, though listed as "back order." Also, NiteCore has one, the HA20. Fenix apparently has 8 different headlamps with a red LED.
Thanks night.hoodie. The reason I posted this thread is because the H502PR is on backorder. I'll look at the HA20, didn't know about that one!