Well, it's a 300watt PSU, couldn't have very good amps on it. I'd agree with RedRaider_gamer - give us some system specs. You begin mentioning about the Seasonic but you jump right into talking about the Antec. What is it exactly that you want to know?
If you are confused about the various ATX connectors than take a look at this:http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20