If you want some more opinions don't be afraid to check out the review section of the site as well. http://www.pbnation.com/reviews/cate...l_air_systems/
As far as ordering an LP system, most come set HP but those that require a shim/spring kit can be ordered at an LP setting. You would just need an HP kit later on if you ever needed it. Ninjas come set to HP stock then you just remove the shims yourself to make it LP.