'啲一格格嘅文' - This is ripstop jacket. Quick dry & light weight. Not commonly used but can be found by P-company selection. I don't like this jacket coz it has a lot of white dots as worn out.
In fact, the fabric for para jacket, arctic smock & field jacket is different.
For the trousers, yes they have different combat trousers. I think the one you used is for tropical. The british army has cold weather combat trousers that issued in early 80s'. However, I don't think soilder 2000 has cold weather trousers coz they have thermal trousers - the softtie.
You can still found the cold weather combat trousers in the market. I have one and I like it very much. However, it's too warm to wear in the Hong Kong.