What type of power supply should i use for led strip?
There's a company called UL that certifies electrical devices for safety and publishes several standards related to electrical safety. You can read about Class 2 Power Units in more detail but in general they are isolated and should be a good choice for safety. 

Personally for the sake of saving a few dollars I'd stick with a power supply that has been UL certified rather than one of unknown origin / safety and it should have a mark such as the following:



You're correct that I.T.E stands for information technology equipment. There's a related question here Why are laptop power supplies marked “IT equipment only”? and while they may work OK you'd be best to avoid using them for other purposes.