I know there was someone on here creating a version of Android called Guardian ROM. I am wondering if there are other options available as the aforementioned GR, maybe things a lot more far along than it is.
As far as a plug and play rom, I have not heard of one. I am looking forward to guardian rom but like you I need something more developed than GR is at the moment. My current setup is Cyanogenmod 11 since it has full SELinux support and they have Privacy guard where you can set strict permissions. Also you can use cyanogenmod without google apps. Mike Perry made a great write up on his blog about hardening android https://blog.torproject.org/blog/mission-impossible-hardening-android-security-and-privacy I have pry-fi which spoofs your MAC on boot but it has to run as root. Cyanogen also has whisperpush on it which made by whisper systems and encrypts messages between other whisperpush users and textsecure users.
https://prism-break.org/en/subcategories/android-operating-systems-mobile/ Though, of the stuff out, I'd have to say Cyanogenmod. Guardian Rom is interesting, but I think it's pretty limited at the moment to only a few devices (someone can correct me on that if wrong, I haven't followed it in a while). But then also you have to pick what apps you use: https://prism-break.org/en/categories/android/ F-Droid is great too for open source stuff.
Agreed, I also use aptoide to get some apps like Redphone. I believe aptoide is now open sourced as well