I realize my suggestions for a lens isn't what you are looking for as they can't be purchased off the shelf ready to thread into the end of a common laser pointer, but if you have something made custom for you by one of the members here who can do that, it's something to consider if you don't mind a fat beam. My crazy 6 inch diameter collimation lenses are not commonly used on a laser, or even inside a laser beam expander, the largest most people use is about an inch to inch and a half. That's more than enough for most any diode we have, I just like to go to extremes.
PCX lenses are good, but If you can find an aspheric lens which is AR coated even better, but stay away from cheap Chinese aspheric lenses made for LED's, those are terrible, they get their aspheric shape from a mold and use cheap glass which due to temperature variations within them as they cool, have inconsistencies within the glass which don't show up when used with LED'S, but when used to collimate coherent light produce swirl patterns within the beam spot and god knows what happens to the beam hundreds of feet out. Not that it matters to most of us, we just like seeing the beams going across a room or used for burning etc., not wanting to use them outside.
Manufacturers can make molded aspheric lenses which will work well enough for our needs, but the glass used isn't the cheap stuff commonly used for LED lenses, and the manufacturing process is tightly controlled to keep the index of refraction more consistent throughout the glass.
