I have a P20 on my belt every day at work. It's a great light. Bright enough for me to check out basements, crawl spaces and unlit closets. The battery life seems to be pretty good, too. I'm not sure if it's regulated, or direct-drive. It came with an interchangable lens system. The one it has installed stock from the factory is the narrow beam lens. A wide angle beam lens was supposedly available, but I never bought one.
The belt clip is sturdy, and removable with an allen key. I put mine in a holster that originally came with a mini maglite. It's a tight fit at first, but after a day, it streched out, and the clip holds it securely in place.
Unfortunately, Lightship Enterprises no longer makes flashlights. If you want one, you'll have to find a dealer who has some leftovers. There's a CPF member (Phil Elmore?) who was a seller of these lights. I think he ran a discussion board or something called "the martialist". He may be able to help you and give you more info.