LG G3 Custom ROm & Stock Rom ( Camera Apk, Battery Drain etc) topic

Hi everybody. I know there is many similar threats like mine but i after a big search iam confusded. i have bought my LG G3 D855 2 weeks ago. I am actually a big fan of Custom roms like CyanOgenMod but the problem is the Stock Rom of Lg G3 Has an awesome Camera Apk.. I was looking if there is a possibility to install A custom Rom and install the stock camera of Lg G3 . So far i found only for G2.. And Besides the camera there is a huge difference between stock and custom rom in LG G3.. In battery Drain and especially In the Ram management... I have the g3 with 2 GB Ram and it eats the 70-80 % . Any help an idea is appreciate .. Sorry for creating a threat which may already been created.