What utilities and tactical are u general using ? i can t find no guide around...

Ty in advance

This thread here: http://www.swtor.com/community/showthread.php?t=986813

has all the up to date gearing advice you need for lightning sorc (1895 min alacrity, 2500 as an option). At 1895 alacrity, when you stack your alacrity buff up to 5% your GCD goes down to 1.3 seconds. 2500 is for making your GCD 1.1 seconds when polarity shift is up.

For tactical most people recommend stormwatch, though eryin's haste is probably useful in some circumstances too.

As for the skills you use in PvP, this video has a decent overview on skill priorities:

Except ideally you'd activate recklessness later after thundering blast is casted, so it'd go something like affliction -> force speed (to get the gathering storm damage buff), -> polarity shift -> Thundering Blast -> recklessness -> chain lightning as ideal, then follow the skills in the video above. Bear in mind that sometimes you don't want to dot someone up, like a juggernaut in enraged defense mode, or someone you want to cc with whirlwind.

Utilities I prefer these ones here:

Except I like force mobility over corrupted barrier. The key utilities IMO are the stun bubble, force speed removes all slows, that utility that lowers force speed cd and makes force barrier stronger, and possibly instant whirlwind.