makeing an assasin nead some help

[korinthVloss]

ok we are starting game play at ECL 12 so i was thinking +1 la to go FERAL (ss page 115) +2 la to be a githzerai (psi hand book page 11) 1 level ninga, 4 levls rogue ,4 assassin but i think we can do beter (the dm has throne favord classes right out of the game so its a free for all of class mixing)

[Ernir]

Initial questions:
Does the game give out free +3 LA? If no, being a Feral Githzerai is going to cut more into your number of class levels than it's really worth, so are you married to that racial concept? Even if you can buy back (http://www.d20srd.org/srd/variant/races/reducingLevelAdjustments.htm) the LA, it's going to leave you behind for a very long time.
What sources are available? Particularly, does the game use Tome of Battle? The Swordsage can make an excellent addition (or replacement) for assassin-type builds.
Do you want to be an Assassin (the class) or an assassin (the concept)? It is possible to build the latter without the former.

You should know that if you can improve the spelling, capitalization, and punctuation of your post, it is likely to improve the amount and quality of the feedback you receive. The post is rather difficult to understand right now.