A little question (yes or no question) from a little french people :) ( i am new in the game )

[newein]

Hi guys, i buy the game and i have Orange box( with HL²+ episode 1+ episode 2 + portal + tf2 + hl² lost coast + hl2 death math )

So i was wondering if i need to install every thing to have the best experience in the game ? and wondering if i need to install SDK source too to have the best experience in the game ?

NB 1: By saying experience i mean to play with no crash and with all the items i can get. Cause i install gmod but when i played i had some weapon of th2 ( the new one who comes with the up dates ) was purple and black. I could see their real color.

NB 2: Sorry for bad english, i am french and french people are knowed to have a bad english.

NB3 : Ty for your help guys :)

[brickbox]

Install all the games.
No need to install Source SDK unless you want to create maps.

[newein]

thnx. I am installing everything : ) have a good day see you in game ^^