There are some more on eBay, many with a "line" output. If they have a line output, you can most likely just remove the line generating optic in there if you need a dot.
Unfocused and used as a flashlight, 50mw wouldn't be too "bright". Why not just get a 1W 808nm diode? Is total invisibility really necessary? You could also even just use a powerful IR led. I have a 5W one at home with no use. I'd be willing to trade for something...