Xposed Framework works fine on the rooted Gionee M2.
While several modules (like Xprivacy) work, GravityBox via Xposed download fc's, use the GravityBox Apk instead
As for M2 Stock ROM, I suggest take a backup of your own phone ROM, there is little chance that Gionee will make stock ROM's available for M2 (a very new device) anytime soon.
For other Gionee ROM's (stock) external sites like androidXDA have a few ROM's for download but none for M2
There are no custom ROM's for M2, if you want a smoother/cleaner experience try uninstalling some bloatware and change the DPI using an Xposed module.
I'm a newbie to android. i have rooted my gionee m2 and flashed AOSP rom. i want to try xposed framework. But dont know how, so pls tell me