Samsung Galaxy S3 (Straight Talk, Build H1) Jelly Bean 4.1.2 to 4.4 KitKat

So I've successfully rooted my Samsung Galaxy S3 from Straight Talk using TowelRoot and have installed SuperSU. I now want to upgarde to KitKat 4.4, but don't know where to start? I've done alot of reading on this and I understand I have to basically download a ROM of KitKat 4.4, but I am wary as to which one to download and how I go about installing it. I don't want to brick my phone.

If that's not possible or too dangerous, I would at least like to remove all the stock bloatware that came with my phone. My baseband/build number ends in H1, if that is relevant at all.

Thanks!