All Quick Charge 2.0 chargers should be the same. I had the official HTC Rapid Charger 2.0 and returned it because the Tenergy charger was half the price and charged just as quickly.

Also, the Tenergy has a LED that tells you when QC 2.0 is enabled, which is kinda useful.

I have this one and it works as advertised.

I bought this amazon one for half the price and it works great.

Its not HTC branded but it still has the quickcharge 2.0 technology http://www.amazon.com/Tenergy-Universal-Adaptive-Qualcomm%C2%AE-technology/dp/B00OVD3FEU/ref=sr_1_1?ie=UTF8&qid=1420981574&sr=8-1&keywords=quickcharge+2.0

So this one? http://www.amazon.com/Tenergy-Universal-Adaptive-Qualcomm%C2%AE-technology/dp/B00OVD3FEU/ref=sr_1_12?s=wireless&ie=UTF8&qid=1417787570&sr=1-12&keywords=tenergy

The HTC One M8 does have Quick Charge 2.0 support. I currently use this Tenergy charger and it works great. No idea how many amps it is pulling though. No idea if yours being an Asian version makes any difference.

Edit: Qualcomm has a list of supported devices and checking it I don't see that versions make a difference.