How do I root GS3 on Linux Xubuntu with Heimdall?

So I have a phone different than most people. See.. I have a Samsung Galaxy S3 SGH-1747m, but most rooting tutorials are GT-I9300, I cannot seem to find any way to root my version of the Samsung Galaxy S3. I was wondering if there was a way I can root and flash my phone in linux with Heimdall. And also I am not good with coding in terminal so I really hope someone explains to me in a simple way. I do not have Heimdall downloaded but I will first show my version of my linux so that I download the right one.

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.2 LTS"
NAME="Ubuntu"
VERSION="14.04.2 LTS, Trusty Tahr"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 14.04.2 LTS"
VERSION_ID="14.04"

My phone version is 4.4.2.

In terms of roms, I do not know anything about them, so I just would say, whatever is the best rom, I would use it.
So yeah, I just need help from someone experienced with Heimdall and Linux that could help me root and flash my phone. Thanks in advance if you guys help me :D