I play alot of hard rock to metal kind of stuff like Underoath, The devil wears prada, As I lay dying etc and I was wondering what would be the best strings to get that will give me the best tone for that style of music? eg. sizes and brands. I also have a schecter c-1 hellraiser if that makes a difference.
D'Addario makes good sets. I use .010's for standard, .011's for D, and .013's for B tuning.
Just make sure you have the correct gauge for downtuning:

E standard and Drop D: 9's/10's (though I use 11's)
D standard and Drop C: at least 11's
C standard and Drop B: at least 12's
B standard and anything below: 13's

This is my guideline for strings.
BTW, I like Ernie Ball strings, they don't break as easily as my last set of GHS Boomers.
Fender American Special HSS Stratocaster
Ibanez 1987 Roadstar II Deluxe
Yamaha THR10X
Marshall JCM900 SL-X
Ibanez WD-7 Weeping Demon Wah
TC Electronic Polytune
Seymour Duncan Tweakfuzz
D'addarios will not break on you. 9s for E-standard, 10s for D, 11/12 for C. For Drop D or C - Ernie ball do heavy bottom, light tops, which are good for that kinda stuff.
I play the kind of screamo you're talking about (Underoath, Emery, AOF...). For the last 4 years I used D'Addario XL serie strings, and recently gone back to Ernie Ball's 9-46 (the orange pack). I don't know how I did manage to play without it for 4 years...Those strings are the best out there, you can down tune it how you want and it will stay in tune, simply the best out there.
ive been playing for almost 18 years and for the last 10 ive been using dadderio but i recently discovered dunlop strings and i think they are just as good.
i use 11-50 dunlop strings and tune half a step down drop c i use 11-52
Member of the Schecter Hellraisers
Esp Ltd KH-603, Schecter c-1+ and Epiphone Les Pauls
Carvin amps, Sperzel Trim-Lok, Emg active pickups only, Tonepros bridges.