1.Check in the CM 11 thread if you can upgrade to 4.4 from 4.1.2 because in my case I needed to above 4.1.2 to flash 4.4 *I was coming from 4.3 *
2.When you flash a custom rom,you don't need ariza patch because the kernel which the ROM uses is already patched and I think the modem is too,so you will be good without it.
3.Make sure you have the latest recovery , I recommend you Philz
Recovery above 6 versions.
Samsung S3 (Resurrection Rom Remix 4.4 with Boeffla Omni Kernel)