HK Edition is Sprint, which is a CDMA carrier, and the M8 Sprint version is CDMA/GSM. While all hardware is the same for the GSM versions of the M8, the CDMA version actually is different hardware. You do not want to be using the HK version on T-Mobile. Its very likely you will not be able to add the proper network support, as I'm guessing the radios for the CDMA version will not include T-Mob's AWS LTE and 3G bands. Aside from the color and headphones, the "HK" features are in software, which can be applied to any M8.
You are basically better off with any version of the M8 besides
Sprint/Verizon. But to guarantee the proper network support, just buy the T-Mobile version.
---------- Post added at 01:27 PM ---------- Previous post was at 01:25 PM ----------
Originally Posted by andybfmv96
And also wondering if I could s-off and flash the T-Mobile ruu
Absolutely not. As mentioned the T-Mob and Sprint versions are different hardware. Software is not compatible, and folks have bricked their phones trying to put GSM software on the CDMA M8.