I haven't been to Nepal but walked hours in extreme rains many a time. a good quality rain jacket and a pant along with fully water proof shoes to cover yourself. I do not use dslr during the rains, so can't suggest, however phones are generally water resistant these days and I have used them without any issues. let me know if you want know the brand of shoes and raincoat i use during rains
Here i have shortlisted few things if it’s helps 1.gopro
2.mobile rugged protector
3.waterproof bag and rain cover 4.proper raincoat or poncho
5.dryfit clothes 6.microfiber towels 7.rugged speaker
Water resistant shoes, a raincoat of course, some plastic protection gear for your mobile and camera. sunglasses and a hat. A waterproof bag. You can buy all this from Decathlon.