Seeking women's hiking boots for Annapurna base camp trek

[Perns]

I am planning to do the Annapurna base camp trek in november (10 days), only carrying a light daypack, walking on mixed terrain, lots of rocks and uneven steps and climbing. It's unlikely to rain although there may be some snow at the top. I have good ankles, but my foot is long but narrow in the heel/ankle, and i'm fairly flat-footed. I'm looking for a pair of mid-cut lightweight waterproof hiking boots with vibram sole, with good traction/grip on rocks and loose gravel when ascending/descending.
I have found Merrell shoes comfortable for my narrow flat foot in the past. I was wondering if anyone knows if any of the following Merrells would be good for the ABC trek, & if so which one?
- 'Siren waterproof mid leather boot' or the
- 'chameleon arc 2 mid waterproof boot' or
- 'chameleon arc 2 rival mid waterproof boot'

We can't get these in Australia so I will be trying on the shoe versions for size and then ordering the boots online from US. Anyone know which boot would be best?
Or any other suggestions with of other brands that do good shoes for flat narrow feet would be most welcomed
With thanks