They make both lamps and ballasts. They all have great reviews on 1000bulbs.com and Elightbulbs.com.
Plusrite also makes some fixtures which you can see on the homepage.
http://www.plusriteusa.com/Plusrite and PLT both sell very inexpensive HID lamps and ballasts on 1000bulbs.com. So I am wondering, are they both legit companies that make good quality products? I have heard Plusrite is usually very good but what about PLT?