Looking into buying a laser

I was recently at a concert and this guy had a laser that made the WHOLE ceiling full of little lasers. His also made the beam visible through the air. Although I am very new at these lasers I would like to get one that can fill up a ceiling with hundreds of laser points.

I am pretty sure this is exactly what he had : Amazon.com: QQ-Tech® 5mW 5in1 High Power Green Laser Pointer Pen with 5 Star Constellation Projection Caps 5 Patterns of Stage light Infinite Pleasures: Electronics

Is this a decent one to buy?..or is there other ones with an advantage? I am looking to get a green and red one, than possibly the "UV colored" or blue one.

I took a look at the link you provided, and it looks to me like your basic 5mw pen . For the price it probably won't be the best one you could buy. But if your looking for cheap, ya found it.
Just about everyone here at LPF will tell ya to "get yourself some laser safety goggles" Even a lot of the cheap 5mw laser are overspec. and can cause damage to your eyes or someone elses eyes.