Yes, I think you are looking in the right category. Thorung La is about 17,000 feet, so that means that you need to be prepared for some cold, some rain, and some old snow (which depends on the monsoon season).
Personally, I would not take the very heavy boots, nor would I take the low-cut runners. A mid-height boot would be good. Take a good selection of socks for different combinations, and take some thin plastic sacks to put between inner and outer socks in the event of major rain and mud.