I think you may need some clarification.
There are actually three manufacturers of low profile pop-up head lamps.
The original creator of the design is k.g. works out of Japan. They are still available through RSpeed but at $1250 USD they are not popular over here.
BrainStorm (BSP) stole their idea and created their own kit. While significantly less expensive it was also cheaply made. They made a slight improvement later on but are still just so-so in quality.
Moss answered the market's request for a low profile kit that was better quality. Moss' kit is considered to be the best bang for the buck in low profile headlamp kits. They are as close to plug and play as you can get too.
Regarding Moss vs. BSP, you get what you pay for. You may find BSP lo-pros on the used parts market likely because the owner is upgrading to the Moss kit. Just remember that the BSP kit basically sucks when compared to the Moss kit and most people who have owned them, can tell you to spend the little bit extra for the Moss kit.