Not possible. Most modded controllers are priced for 80$+ as far as I know. Unless you have like a close friend or so who can mod controllers, you are out of luck.
Why do you even need a modded controller? COD is so fucking easy. Quickscoping I have a natural talent in , rapid fire is just gay since it ruins your cover completely and people call you a pussy for using it, drop shotting is very simple with Tactical layout, and fuck breath holding.
I bought like 3-4 regular controllers in total, all of them broke. The one I recently bought from Radioshack broke from my nephew dropping milk on it (yes, I know. I was so fucking pissed, but he cries to play his LEGO games...). Believe it or not, I still play with the default controller I got with my PS3 around 2 years ago. Really worn out though, but still in like a 7/10 condition.
Nice story, isn't it?