Buying Steam Product Activation Codes (RSGP)

Looking for a couple of game activation product keys on steam:

Left 4 Dead 2

Call Of Duty WAW

Call Of Duty 4

Dead Island

Day Of Defeat

Assasins Creed 2

Mafia II

Metro 2033

Homefront

Feel free to add me on MSN or post here. I'll go first to people who are more vouched than me or if you don't feel comfortable, We'll use a MM.

This is my first time posting looking for Steam products so if there is something against the rules (already read, didn't find anything against it) or if this is not possible / steam product activation codes don't really happen that often, go ahead and let me know .