If it comes from Aliexpress it will probably already be English (and maybe other languages optional also) and compatible with English NVRs. I've bought lots of different types from aliexpress and except for 1 time of the wrong lens being sent which was minor for me, never had a problem.
I bought my 4Ks from a seller on aliexpress after asking some questions and they were multi language and work with English NVR/iVMS etc - and I checked them out good. Well worth it (for me anyway).
Hell you can always ask the supplier if you are concerned.
I wouldn't update the firmware it comes with though - though mine aren't Internet accessible.
The price difference (especially for 50 cameras) is so huge that it would be well worth it for me, but of course it depends on the job and only you know if it's worth it for you.