Newbie: help needed in upgrading CM on resurrection remix n7100

entlemen, I am quite new to custom OS on Android but have fair share of knowledge related to IOS.

I installed CM 6 on my android and installed resurrection remix OS. Now I am not able to update to CM 12.

What I did:
1) downloaded latest nightly build from Cyanogenmod.org
2) saved in external memory
3) installed it via recovery mode.

The result was error and some status 7 message came. Thanks to the backup, my phone is good and working.

What I want to do:
1) upgrade to CM 12 or best stable ROM
2) install ios7 theme via xpose repo

Any help is really appreciated.


Thank you