Yes there is a competitive FIFA forum depending on the platform. Find me on #complexity and we can discuss that.
FIWC, or the FIFA Interactive World Cup is FIFA's most prestigious tournament on console. It often switches (if I'm not mistaken) between PS3/360, but this past year it was on PS3.
The top FIFA PC league is ESL. There is a program/patcher called "ESL Online Patcher" version 0.35 by Lupus which patches your game automatically to the settings that have to be used for competitive play.
And finally if you want to get going, get the patcher from ESL, connect to Quakenet on IRC, join #esl.fifa, and start looking for friendlies.
You can find me, coL|eafra, coL|Barmoa, or coL|Wizakor on IRC if you have any other questions.